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.
Episode 1
Shoichi is an average guy who has trouble visualizing his future. When he sees how far ahead of him his classmate, Hikari, is in every facet of life, he makes a decision.
Episode 2
The girl who climbed in through Shoichi's window wasn't a ghost, but his classmate Hikari. Her appearance at the summer course rejuvenates him.
Episode 3
Shoichi and Hikari spend more time together during the summer course and eventually end up in the men's bath together after he incorrectly calls her bluff.
Episode 4
Hikari continues to ignore Shoichi after their moment at the pool, leading him to suspect he did something wrong.
Episode 5
Shoichi and his two friends have been playing video games during class and talk about it has been spreading across the school. Eventually, a girl noticed them playing and enjoyed playing with them. She was secretly into video games as well. The four of them later go into town and play some karaoke and arcades.
Episode 6
Two childhood friends duel out there differences over a game of GusGal.
Episode 7
Shouichi was invited to Miyamae's place to play some GusGal, but instead, they talked a lot more and she began to open up to him.
Episode 8
Previously Miyamae asked Shouichi to come with her to ComiMa, a fashion and gaming convention. Now along with Shiori's custom cosplay outfits and Tomoe, all four of them go and try to sell some of their creations. After a long day, they go to dinner and ran into a classmate that happened to work there.
Episode 9
A new arc kicks off, as Shoichi and Kyoko both struggle to come to terms with each other's growing up.
Episode 10
Shoichi is spurred on by various events happening around him to ask Kyoko out on a Christmas Eve date.
Episode 11
Shoichi and Kyoko agree to remain friends forever, but Ikuo's stirring display of bravery awakens something within Shoichi.
Episode 12
Shoichi, having decided to go out in a blaze of glory, lays it all on the line to tell Kyoko how he really feels.
