For high school students like Shouichi Kamita, university entrance exams and the future are common concerns. It is also during this time in life that a mysterious emotion that vexes people of all ages may begin to weigh upon one's mind—love. At this point in his teenage years, Shouichi finds three girls he could see himself having a future with: the ever-cheerful Hikari Tsuneki, who teases Shouichi without mercy, but actually has a softer side; the competitive gamer, Tooru Miyamae, who has difficulty communicating with others; and Shouichi's childhood friend, Kyouko Touno, the sometimes immature shoujo manga enthusiast. Seiren follows Shouichi's relationships with these three girls across three separate arcs, as their feelings grow from mutual interest and blossom into something more beautiful.

Does the girls' daily life include fighting and not fighting? All the characters from the TV animated series "Katana Maidens" and the smartphone game "Katana Maidens Kizamishi Issen no Tomoshibi" are gathered together in smaller form!

Ueno may be the president of the science club at her junior high and a genius inventor, but she still can’t figure out how to confess to her crush, Tanaka! Can she find a way to give her heart what it truly yearns for?

Buntarou doesn't know what he wants to do in the future. He does not have any kind of dream that he wants to pursue, so currently he just spends his days hanging around with his friends. One day, his classmate Sayuki asks him if he wants to help with development of a gal game. She says that she had become interested in his help after she read one of his works intended for the drama club. Buntarou doesn't know anything about gal games, but Sayuki claims that she has the ability to make it a success. Can they make the game, and will it be a success like she claims it will be? This is the story of youths taking a daring step into the unknown...

Akira Tachibana is a soft-spoken high school student who used to be a part of the track and field club but, due to an injury, she is no longer able to run as fast as she once could. Working part-time at a family restaurant as a recourse, she finds herself inexplicably falling love with her manager, a divorced 45-year-old man with a young son. Despite the age gap, Akira wholeheartedly embraces his mannerisms and kind nature, which is seen as spinelessness by the other employees, and little by little, the two begin to understand each other. Although unable to explain why exactly she is attracted to him, Akira believes that a concrete reason is not needed to truly love someone. On a rainy day, she decides to finally tell her manager about how she feels... but just how will he react?

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.

The story revolves around a highschool boy named Niwa Makoto. He lives with his aunt's family since his parents are away on business. It is there where he meets his mysterious cousin of the same age Touwa Erio — who happens to tie a futon mattress around her upper body and is a self-proclaimed alien. Her staple food is pizza. Erio had been missing for half a year and was found floating in the sea. She doesn't remember anything about what happened during that period of time, but she began to think that it was the act of an alien and wanders the neighbourhood wrapped in the futon.

Set in a world where witches run havoc, the military decides to shift from using sword to utilizing guns to neutralize magical threats. The Anti-Magic Academy is an institution that specializes in training witch hunters. Takeru Kusunagi, who can’t use guns and continues to fight with a sword, is relegated to the 35th Test Platoon, a motley group who can’t cooperate. One day, Ouka Ohtori, an elite pistol master who was forced into demotion, joins the platoon. Will they be able to gather their strengths and work together?