disclaimer: tags/genres grabbed from aniDB and/or ANN. I haven't watched the anime myself yet.
comedy action romance sci-fi school life drama fantasy adventure ecchi short episodes sequel
Kochinpa!/Aira - Pachinko & Slot Island

[short 1min]
Prince of Stride - Alternative
Stride is an extreme sport that involves six people in one team who run relay races through towns. Teams from many schools compete to win Japan’s top Stride competition, End of Summer. Fujiwara Takeru and Sakurai Nana are first-year high school students at Hounan Academy who attempt to restart a closed-down Stride club, but they must recruit six members for the team. They ask Yagami Riku to join, but he turns them down by saying that Stride is the one thing he doesn’t want to do. However, Takeru and Nana drag Riku into the clubroom, trying to convince him.
sports, tournament
Musaigen no Phantom World/Myriad Colors Phantom World
In the near future, in a world born of human imagination, what humans would call ghosts or monsters appear, and they come to be called "phantoms." Ichijou Haruhiko is a first year at Hosea Academy along with his upperclassman Kawakami Mai, who fights phantoms with the ability "Spirit of Five Elements," Izumi Reina, who has the ability "Phantom Eater," and Minase Koito, who fights phantoms in solitude. They experience the ups and downs of high school life before a certain incident leads them to the truth of this world.
supernatural, action, comedy
Sushi Police
With the 2020 Tokyo Olympic Games around the corner, there’s also a worldwide sushi boom! But what to do with all the bastardized sushi out there? The Japanese Government’s urgent response is to team up with other ruling powers around the world to establish the WFCO (World Food-culture Conservation Organization) to protect and promote authentic local cuisine. And so the World Food-Culture Conservation Organization (WFCO), deploys its 9th Division to oversee Japanese cuisine abroad. The 9th Division, a.k.a. Sushi Police, is notorious for their aggressive conduct and they hassle anyone serving unauthentic Japanese food in the U.S., Russia, France, China, etc. They will resort to any means necessary to eliminate bad sushi. Soon they are despised by restaurant proprietors around the world.
[short], action, comedy, drama
Haruchika - Haruta to Chika wa Seishun Suru
Haruta and Chika are members of their high school wind instrument club that is on the verge of being shut down. The two are childhood friends, and they spend their days practicing hard while also trying to recruit new members. When a certain incident happens within their school, they work together to solve it.
music, mystery, comedy, romance
Norn 9 - Norn + Nonetto
The era where great powers of the world have all ventured overseas. Revolution and liberalism spread all over the world. Right when souls and earth are ill, a glowing sphere appeared in the sky, and removed the borders of the world. Three girls and nine young men depart together with a flying ship.
drama, romance, sci-fi, reverse-harem
Active Raid - Kidou Kyoushuushitsu Dai Hakkei
Set in a part of Tokyo that has descended into a quagmire, the story follows Unit 8 of the 5th Special Public Security Section’s 3rd Mobile Assault Division . popularly called "The Eighth" . who don powered armor "Willware" exoskeletons to counter the rise in crime.
sci-fi, mecha
Shoujo-tachi wa Kouya o Mezasu
Houjou Buntarou is a student who wants to be something, but doesn’t know what. One day, his classmate Kuroda Sayuki announces she is working on a bishoujo game and requests his help. Sayuki scouted him because he wrote a good script for drama club, but Buntarou doesn’t know anything about bishoujo games.
school life, comedy, romance
Boku dake ga Inai Machi/ERASED
Fujinuma Satoru is a struggling manga artist who has the ability to turn back time and prevent deaths. When his mother is killed he turns back time to solve the mystery, but ends up back in elementary school, just before the disappearance of his classmate Hinazuki Kayo.
mystery, time travel
Ojisan to Marshmallow
The story revolves around Hige, a middle-aged man who loves marshmallows, and Wakabayashi, an office lady who loves Hige and enjoys teasing him with the snack. The anime follows the two as their relationship develops at the workplace.
[short 5min], comedy, romance
Phantasy Star Online 2 The Animation
Itsuki Tachibana is a student of Seiga Academy, a co-ed boarding high school with excellent reputation, located in a suburb outside the city center. On a day of second semester, he was summoned by Rina Izumi, the most esteemed and praised chairperson, to the student council room, without knowing what awaits him.
romance, sci-fi
Dagashi Kashi
Shikada You owns a rural sweets shop, and his plan is for his son Kokonotsu to take it over one day, but Kokonotsu wants to be a manga author instead. One day, the heir to the well-known sweets maker Shidare Company, the cute but weird Shidare Hotaru, pays them a visit. Apparently, You is famous, and she wants him to join her father’s company, but he will agree only if she can convince Kokonotsu to inherit the shop and continue the family business.
comedy, romance
Divine Gate
After the Divine Gate opened, our world and the worlds beyond became connected, bringing an era of chaos. To restore order, the World Council was formed and the Divine Gate fell into legend. Now, a select few have gathered to attempt to reach the Gate and remake the world.
fantasy
Oshiete! Galko-chan
Galko, Otako, Ojou. are a "gal," an otaku, and a proper lady, respectively, and are also good friends. The three high school girls with different perspectives discuss the kinds of secrets you can’t tell boys.
[short 8min], comedy, school life
Sekkou Boys
Sekkou Boys is a unit of four stone figures . the military saint and group leader Saint Giorgio, history’s original celebrity Medici, the strikingly handsome and multi-talented Hermes, and the god of war Mars who is earnest about love . who become idiosyncratic idols. The story depicts their efforts to make it in the entertainment world with their female manager Ishimoto Miki, who just graduated from college.
[short 8min], comedy
Tabi Machi Late Show

[short 8min]
Koukaku no Pandora
When Nanakorobi Nene, a cybernetically enhanced girl-next-door, heads to the island metropolis of Cenancle to live with her aunt, she has no way of knowing what’s in store for her. A chance meeting intertwines her fate with that of the super-rich inventor, Uzal Delilah, and her adorable and grumpy companion, Clarion, who happens to be a cyborg just like Nene. Nene is thrilled to make a friend, but there’s more to Uzal and Clarion - and the island of Cenancle itself - than meets the eye. When a super-powered terrorist threatens Cenancle, Uzal claims that the only way to avert disaster is for Nene to team up with Clarion and use their combined powers - abilities Nene never even knew she had.
sci-fi
Reikenzan - Hoshikuzu-tachi no Utage
A comet falling will bring about a great calamity, and in order to choose a child fated by the falling comet, the family of the "Reiken" clan with a long storied history is once again resuming its entrance examination process to find disciples. The protagonist Lu Wang, who possesses a special soul that is only available once in a thousand years, decides to take the exam, and he starts down the path toward becoming an exceptional sage.
comedy, fantasy
Shouwa Genroku Rakugo Shinjuu
The year was 1970s. Fascinated by the performance of rakugo master Yakumo the 8th at a philanthropic show in a prison, delinquent Kyouji visited Yakumo immediately after serving his term, begging Yakumo to take him in as an apprentice. To his surprise, master Yakumo agreed without much hesitation, yet things progressed not quite as Kyouji expected.
drama
Bubuki Buranki
Returning to Japan after having been away for 10 years, Azuma Akira finds himself attacked and captured by armed strangers. What saves him is his childhood friend, the girl Ougon Asabuki, and the Bubuki that had become her right hand.
sci-fi, action, drama
Luck and Logic
In L.C. 922, people faced a sudden crisis. In Tetra Heaven, the land of legend, a hundred years of war had come to a close. The gods who lost the war searched for a new place to live, and found it in Septpia, the human world, which they proceeded to attack. The Logicalists attached to ALCA, a special police agency whose duty it was to protect cities from assaults by foreigners (angels), were compelled to act in defense of cities, whether they wished to or not. Depending on their ability, Logicalists could initiate trance with goddesses from the other world, and stand a fighting chance on the battlefield. A civilian named Yoshichika Tsurugi, who lacked "Logic" and lived happily with his family, was caught up in an attack, and took shelter along with many people. He meets a beautiful goddess named Athena. In her hands, she had the "Logic" that Yoshichika lacked. Now both Yoshichika and Athena head to their destiny.
magic
Niji-iro Days/Rainbow Days
Natsuki, Tomoya, Keiichi and Tsuyoshi are high school students and close friends. The four boys have no club activities, and they hurry through their studies so they can spend their days having fun. Their main topic of interest is love. Natsuki has an unrequited crush on Anna, a girl from another class, and his friends keep meddling in their relationship.
comedy, romance, daily life
Ooya-san wa Shishunki!
The protagonist is living alone for the first time after finding employment. At his tiny, no-bath apartment he finds a landlord who looks like a little sister. She does the cooking and housework, so sometimes she seems like a grandmother, but she also enjoys a normal middle school life with her friends.
[short 3min], comedy, daily life
Dimension W
Humanity harnessed a new inexhaustible energy from inventions called "Coils" in 2051. In 2072, a skilled recovery specialist named Kyouma Mabuchi encounters a mysterious, beautiful woman right in the middle of a certain job. It is a fateful encounter that opens the door to the new dimension "W."
action, sci-fi
Hai to Gensou no Grimgar/Grimgar of Fantasy and Ash
When Haruhito awakens, he’s in the dark. He doesn’t know where he is, why he is here, and where he came from. Around him there are several men and women who have the same circumstances. Haruhito and his companions find themselves in a game-like world called Grimgar and must form a party, cooperate, and learn new skills to survive the harsh environment together.
adventure, fantasy
Schwarzesmarken
Germany was divided into East and West after WWII, where citizens of either treated the other side as enemies. In the midst of Cold War, however, the Earth was invaded by an alien life form landed on Kashgar, Xinjiang Uyghur Autonomous Region, known as "Beta." Now, ten years after the first contact, East Germany, formally German Democratic Republic, has become the front line.
[prequel], action, sci-fi
Saijaku Muhai no Bahamut
Lux is a former prince of an empire named Arcadia that was overthrown via a rebellion five years earlier. Lux accidentally trespasses in a female dormitory’s bathing area, sees the kingdom’s new princess Lisesharte naked, and incurs her wrath. Lisesharte then challenges Lux to a Drag-Ride duel. Drag-Rides are ancient armored mechanical weapons that have been excavated from ruins all around the world. Lux used to be called the strongest Drag-Knight, but now he’s known as the "undefeated weakest" Drag-Knight because he will absolutely not attack in battle. After his duel with Lisesharte, Lux ends up attending the female-only academy that trains royals to be Drag-Knights.
fantasy, harem, mecha, school life
Mahou Shoujo Nante Mou Ii Desu kara
Yuzuka Hanami is a young girl who has few friends but who can do anything. One day, Yuzuka gets accosted by a strange creature named Miton who is digging through a trash dump. Miton tells Yuzuka, "you have the makings of a magical girl" and seems extremely suspicious. When Yuzuka is suddenly transformed into a magical girl, she’s wearing a bathing suit.
[short 5min], comedy, magic
Ao no Kanata no Four Rhythm
In a world where flying is as simple as riding a bicycle, there is a popular sport called "Flying Circus" (dogfight race). The protagonist who once hoped for a future in this sport suffered a setback due to an overwhelming defeat, and withdrew from the sport for this and some other reason. However, he met the transfer student Asuka Kurashina, and in teaching her to fly the skies, the old passion returned. He takes part in the Flying Circus again.
sci-fi, romance
Kono Subarashii Sekai ni Shukufuku o!
Satou Kazuma, a shut-in and die-hard fan of games, anime, and manga, suffers a traffic accident that would bring his disappointingly brief life to an end. However, he wakes up and sees a beautiful girl who introduces herself as a goddess and says: "Hey, I have some good news: would you like to go to an alternate world? You may only bring one thing you like with you." He responds: "So, I’ll bring you." With that, he is transported to another world, and his great adventure quest for subjugating the demon king begins, but first goes the hard work like finding food, clothing, and shelter. Kazuma wants to live in peace, but the goddess raises one problem after another, and the demon king’s army has its eyes set on him.
[after 1st eps], comedy, fantasy, harem
Ajin
17 years ago, immortals first appeared on the battlefields of Africa. Later, rare, unknown new immortal lifeforms began appearing among humans, and they became known as "Ajin" (demi-humans). Just before summer vacation, a Japanese high school student is instantly killed in a traffic accident on his way home from school. However, he is revived, and a price is placed on his head. Thus begins a boy’s life on the run from all of humankind.
[after 1st eps], action, horror
Kono Danshi, Mahou ga Oshigoto Desu.
Chiharu is a wizard in charge of the magic department’s crisis counter-measure division. His days are hectic, but he meets a candid young man named Toyohi at his favorite bar, and the two hit it off. On their way home, Toyohi suddenly confesses to Chiharu. Chiharu is at first bewildered at his unexpected confession, but he starts to fall into Toyohi’s pace, and the two begin to spend more time together. However, after a mistake at work, Chiharu decides to devote himself to his work and pushes Toyohi away.
[after 1st eps], [short], shounen-ai
Rilu Rilu Fairilu: Yousei no Door
"Fairilu" are fairies of flowers, insects, mermaids, or other entities that are born from "Farilu Seeds." All Fairilu are born with their own key, and they must search to find and open the door that fits only their key. Once the Fairilu pass through the doors, they mature. The doors are also related to the human world.
[after 1st eps], magic
Ansatsu Kyoushitsu/Assassination Classroom 2

[sequel]
Gate - Jieitai Kanochi nite, Kaku Tatakaeri (2016)

[sequel]
Durarara!!x2 Ketsu

[sequel]
Nurse Witch Komugi-chan R

[sequel]?, comedy, magical girl
Fairy Tail Zero

[prequel]
Koyomimonogatari

[sequel]-ish, [short]
Yami Shibai 3

[sequel], [short 5min]
Akagami no Shirayuki-hime/Snow White with the Red Hair 2

[sequel]
Teekyuu 7

[sequel], [short]
Ketsuekigata-kun! 4

[sequel], [short]
Ganbare! Lulu Lolo S3

[sequel]
Mahou Tsukai Precure

[sequel]