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
Lance N' Masques
Hanafusa Youtarou, a young man, is part of the last remaining order of knights in the 21st century, the Knights of the World. As he fights as the mysterious Knight Lancer, he must hide his identity behind a mask.
action, fantasy
Young Black Jack
Kuroo Hazama, an aspiring young medical student, studies diligently from Dr. Joutarou Honma, a top surgeon who had saved Hazama’s life when boy Hazama was badly injured by an unexploded bomb. Someday in the future, Hazama will be known as "Black Jack," a surgeon with unsurpassed skills but without a license.
[prequel], drama
Hacka Doll the Animation
Hacka Doll app delivers a customized feed of news for each user. The user answers some simple questions when launching the app for the first time, and then the app will filter the news that caters to the user’s personal interests. With daily use, the app automatically analyzes and learns which news articles the user reads and recommends to further personalize the feed. The anime personifies the app’s customization engine as three "Hacka Dolls" . the personal entertainment AI and main navigator Hacka Doll #1, the anime expert Hacka Doll #2, and the knowledgeable otaku Hacka Doll #3.
[short 8min]
When mysterious monsters suddenly begin appearing all over the city and start preying on human beings, a scientist named Banba Sousuke begins a campaign to unravel the truth of these occurrences.
horror, [short 8min]
Heavy Object
The story revolves around Objects . powerful, massive weapons that change the course of warfare . and Elite Object pilots. An odd Elite girl named Milinda meets Quenser, a student who aims to become an Object mechanic, with the soldier-in-training Heivia on a snowy battlefield.
action, sci-fi
Gakusen Toshi Asterisk
The Academy City on water Rikka, otherwise known as Asterisk, is famous for being the world’s largest stage for the integrated battle entertainment Star Wars Festival. The young boys and girls of the Starpulse Generation belonging to the six academies make their wishes with Shining Armaments in their hands, vying for supremacy, and Amagiri Ayato is one of them. Ayato arrives in Rikka at the invitation of Claudia Enfield, the Student Council President of the Seidoukan Academy. Right after that, he incurs the wrath of the Petalblaze Witch Julis-Alexia von Riessfeld and ends up having to duel her.
action, sci-fi, swordplay, ecchi
Rakudai Kishi no Cavalry
In a time and place where one’s soul can be morphed into a weapon, there are modern day magicians called Mage Knights. Although Kurogane Ikki is a student at an institution that trains Mage Knights, he has no particular talent in magic and is labeled the Failure Knight or the Worst One. Getting way less than average marks, he is forced to repeat a year. But with the arrival of a new head of the institution, a new rule is created: knights whose abilities are compatible, as decided by the board, must share rooms and train together throughout their school years to maximize their abilities. Ikki’s roommate turns out to be Stella Vermillion - a princess of a foreign country and a rank A knight: the type of genius in magic who only appears once a decade. When Ikki walks into the room while she is changing her clothes, it causes a huge misunderstanding that eventually leads to a duel between the two. The punishment for the losing side is the Eternal Submission to the winner. Forced to live the same room and practice magic together throughout their school years, how will Stella and Ikki’s relationship evolve?
action, fantasy, romance, swordplay, ecchi
There are cameras everywhere in the modern world, monitoring our lives constantly. Those "eyes" have seen the world as you don’t know it.
horror, [short 3min]
Shingeki! Kyojin Chuugakkou
The parody re-imagines Eren, Mikasa, Armin, and other characters from the original manga as students and teachers at Titan Junior High School.
parody, [spinoff]
Kidou Senshi Gundam - Tekketsu no Orphans/Mobile Suit Gundam: Iron-Blooded Orphans
300 years after a great conflict between Earth and Mars known as the "Calamity War," a woman named Cordelia sets out on a journey to Earth to speak for the independence of the Martian city of Chryse, which is under the control of the Earth government. Escorting her is the private security company CGS members Mikazuki Augus and Orga Itsuka. When a group named Gjallarhorn attacks CGS and Cordelia, Orga sees this as a chance to rebel against CGS and launch a coup. Mikazuki and Orga are thrust into a new conflict. To fend off Gjallarhorn, Mikazuki rides an old mobile suit from the Calamity War, powered by a nuclear reactor, the Gundam Barbatos.
action, drama, sci-fi
Onsen Yousei Hakone-chan
After a long slumber, a hot spring spirit named Hakone-chan awakens at a spa resort in modern-day Japan. However, she has taken on the appearance of a young girl while sleeping. She interacts with the locals and tries to regain her powers with the help of a high school boy named Touya who stumbles upon her at the hot spring.
comedy, supernatural, [short 5min]
Komori-san wa Kotowarenai!
The story revolves around middle school student Komori Shuri, who is too kind and therefore unable to say no when someone asks her for a favour. The anime follows Shuri’s everyday life and describes how she helps others on numerous occasions.
comedy, school life, [short 3min]
Comet Lucifer
On the planet Gift there are precious crystals called Giftjium buried in the earth. A young man named Sougo Amagi lives in Garden Indigo, a prosperous mining town. Sougo, whose hobby is collecting rare crystals, one day becomes involved in a dispute between classmates Kaon, Roman and Otto. He wanders deep into the ruins of a mine and discovers an underground lake. There, he meets a mysterious girl named Felia with blue hair and red eyes. Who is this girl, and what will their meeting bring?
Concrete Revolutio - Choujin Gensou
In an imaginary age of gods about 20 years after the war, Japan is flooded with all the superhumans ever written about in fictional stories: titans from outer space, lifeforms from a mystical world, phantoms and goblins from ancient times, cyborgs created by scientists, relics that rose out of the ruins of ancient civilizations, and the list goes on. Some of them make no secret of their existence and have gained popularity in the society, while others cloak their identities and fight in secrecy. Naturally, the Japanese government cannot ignore the existence of these superhumans and establishes an organization under the Ministry of Health and Welfare - the Overpopulation Research Laboratory, a.k.a. the Superhuman Bureau. Their mission is to identify and approach superhumans, then oversee and safeguard them. One member of the Superhuman Bureau, Hitoyoshi Jirou, is the protagonist of this series.
One-Punch Man
The story takes place in the fictional metropolis of City Z, Japan. The world is full of strange monsters that mysteriously appear and cause many disasters. Saitama is a super powerful hero who easily defeats the monsters and other villains with one punch. However, after becoming too strong, Saitama has become bored with his powers and is always trying to find stronger opponents who can fight him. On his adventures, he meets new friends, enemies, and his own disciple, the cyborg Genos, and also joins the Hero Association in order to gain fame for all of his actions to prevent evil. Despite defeating many strong monsters that even the Hero Association’s top heroes are unable to defeat, Saitama struggles to gain respect. Most people discriminate him due to his plain physical appearance and some accuse him of being a counterfeit hero. Only a small number of individuals recognize his incredible talent and humility towards others.
action, fighting, parody
High School Star Musical/Koukou Hoshi Kageki
Hoshitani Yuuta enters Ayana Academy, a school focusing on show business activities, specifically music. The academy has a group of three students with the highest grades in the musical department, and they are known as the Kao Kai (Cherry Blossom Flower Association). This organization stands at the top of the pecking order within the academy. The shortcut to entering the musical department is to enter the Star Frame class, which is directly taught by the members, and to be recognized by them. Unfortunately, due to their own problems, students Touru, Kaito, Kakeru, Shuu, and Yuuta are all struggling to even remain candidates for the musical department. By a stroke of luck, however, the five are spotted by Kao Kai member Ootori, and they attract his interest.
JK Meshi!
Three high school girls have mastered the art of cooking simple, B-class dishes called JK Meshi. The three girls . Rena, Ryouka, and Ruriko . are all classmates in their second year of high school. They often get distracted when studying for tests, and when they do, they cook JK Meshi.
[short 5min]
Tantei Team KZ - Jiken Note
Tachibana Aya is a sixth-grader who frets and obsesses over friends, family, grades, and more. One day, she joins the Tantei Team KZ with four very idiosyncratic boys she met at cram school. There is the glib and attention-grabbing leader Wakabu Kazuomi, the mysterious expert of personal relationships Kuroki Takakazu, the smart and stoic math genius Uesugi Kazunori, and the sweet-hearted Kozuka Kazuhiko who is good at social matters and science. Aya finds her place among them as the language expert. Tantei Team KZ gets involved in modern-day cases, and even if they bicker from time to time, they collaborate by pooling each of their talents and skills to solve these cases.
mystery, [short 5min]
Dance with Devils
Tachibana Ritsuka is a female second-year high school student who attends Shiko Academy in Shiko Town. She enjoys her school life while living with her mother Maria, but one day, that balance falls into ruin when she discovers several of her attractive male classmate are demons.
romance, supernatural, reverse harem
Ore ga Ojou-sama Gakkou ni "Shomin Sample" Toshite Gets-sareta Ken
In the romantic comedy’s story, an ordinary high school boy named Kagurazaka Kimito is kidnapped by an elite young lady’s academy to be a sample of the common people. The school is full of sheltered girls who have never met male peers before.
comedy, ecchi, harem
Fushigi na Somera-chan
Somera Nonomoto is a NEET girl with mysterious magical powers known as "Nonomoto’s magic fist," creating numerous problems for her sister Kukuru and her friend Shizuku Tend..
comedy, [short 5min]
Sakurako-san no Ashimoto ni wa Shitai ga Umatteiru/A Corpse Is Buried Under Sakurako's Feet
The story revolves around Tatewaki Shoutarou and Kujou Sakurako. Shoutarou is a normal high school student with a serious demeanor who likes to show off his girlfriend Sakurako. Sakurako is an extraordinarily beautiful woman in her mid-20s from a rich family who loves "beautiful bones". The two live in the city of Asahikawa in Hokkaido, and they get involved in various incidents regarding bones.
drama, mystery, thriller
Taimadou Gakuen 35 Shiken Shoutai/Antimagic Academy 35th Test Platoon
The story is set in a world where people with magic powers are close to being wiped out. Just as the balance of power and military might has once shifted from swords to sorcery, it shifts to guns once again. Kusanagi Takeru goes to AntiMagic Academy, a training facility for Inquisitors of Herectics who crack down on the dwindling threat posed by magic users. However, Takeru cannot use guns at all and can only fight with a sword. As a result, he is relegated to the 35th Test Platoon, the motley "small fry platoon" for students who don’t seem to fit in anywhere else. One day, Ootori Ouka, the ultra-elite pistol master who already has her qualifications for witch-hunts, also joins the platoon.
action, fantasy
Subete ga F ni Naru - The Perfect Insider
The story revolves around Saikawa Souhei, a member of the Saikawa Research Lab. He goes on a vacation held by the lab, and Nishinosono Moe, the daughter of his mentor, joins the group on their vacation despite not being a part of the lab. There, the two end up finding a corpse. The two work together to solve the mysteries of what becomes a serial murder case.
Valkyrie Drive -Mermaid-
Tokonome Mamori is transferred to Mermaid - an artificial quarantine island for people with superpowers. When Mamori is attacked, a newly transferred girl named Mirei saves her. The enemy doesn’t stop, however, and the two are soon cornered. Just when they think all hope is lost, Mirei kisses Mamori, and Mamori turns into a sword. Mirei then wields the sword and launches a counterattack against their enemies.
action, (too?) ecchi
Monster Strike
Ren Homura returns to his former residence, yet he feels very uncomfortable: he possesses no memory of having lived there. Without warning or his permission, a game called "Monster Strike" installs itself into Ren’s smartphone; monsters of the game then literally fly out from his smartphone and start fighting on streets. Watching the fighting in amazement, Ren starts picking up his lost memories.
magic, tournament, [short 9min]
Brave Beats
The story follows Kazaguruma Hibiki, a sixth grader who meets an amusing little robot named Bureikin while coming home from school one day. Bureikin, a dancer from an alternate-dimension dance world, challenged the dance king for the throne and lost. He has been deprived of Dance Stones (the stones of dance power) and sent to the human world. To restore his power, Bureikin must collect all the Dance Stones scattered around Earth.
Ani Tore! EX
Five idol candidates show the audience ways of enjoying physical training.
[short 4min]
Diabolik Lovers More, Blood

Lupin III - L'avventura Italiana

Miss Monochrome -The Animation- 3

[sequel], [short 8min]
Noragami Aragoto

K Return of Kings

Soukyuu no Fafner - Dead Aggressor - Exodus Part 2

Itoshi no Muuco (2015)

[sequel], [short 15min]
Kindaichi Shounen no Jikenbo Returns 2


Utawarerumono - Itsuwari no Kamen

Haikyuu!! 2

Ameiro Cocoa - Rainy Color e Youkoso

[sequel], [short 5min]
Peeping Life TV - Season 1??

[sequel], [short]
Teekyuu 6

[sequel], short 2min]

Yuru Yuri San Hai!

Hidan no Aria AA

[closely linked spinoff?]
Shin Atashin'chi

DD Hokuto no Ken 2 - Ichigo Aji+

Garo - Guren no Tsuki

Shinmai Maou no Testament BURST

Gochuumon wa Usagi Desuka??

Owari no Seraph - Nagoya Kessen Hen

World Trigger - Toubousha Hen

Cardfight!! Vanguard G - Gears Crisis Hen