Seiji Utsumi (内海 聖志, Utsumi Seiji) is the protagonist of the manga series "GE - Good Ending". His development into a more mature person and his changing relationships with his friends serves as the central element of the story.
Seiji is a teenager of average height, he stands at 172 cm. His notable features include his spiky brown hair and eyes.
Seiji starts off as a typical shy boy with no skill in sports. He has become content with watching people from afar without getting too close. At the start of the series, he has a crush on the captain of the tennis team, Shō. Although initially fine with not approaching her, Yuki eventually encourages him to. Thanks to Yuki, has Seiji managed to learn more about how to confront people. Being naturally of kind nature, Seiji is protective of others and is capable of understanding feelings of others.
This trait of him has led to a couple of women becoming attracted to him, namely Risa, who has grown to love Seiji so much that she is determined to save him from all others. Seiji is often found getting into awkward situations, which always lead other people to misunderstand things, forcing him to try and explain himself. tries hard to find ways in passing exams, as well as try hard in making other people happy, even if it means making himself do impossible or foolish things.
Seiji is first shown spying on the beautiful tennis captain, only to have been caught by Yuki, who later gets him to confess his feelings, which in turn benefits them both. To begin with, things turn out smoothly, with Seiji joining the tennis club and also training hard to impress his senpai.
Afterwards, a former senpai of Shō contacts her and, due to having liked him for a long time, Shō ends up going out with him, much to the sadness of Seiji, who is comforted by Yuki.
As the story progresses from then on, Seiji begins growing closer to his advisor and eventually, finds himself falling in love with her. When Seiji finds out that Keito had been using Shō, by lying that he had broken up with his girlfriend, Seiji becomes furious, and while unable to pursue the ex into returning to Shō, the latter comes to find herself growing feelings for her kohai.
After sometime, Seiji and Yuki share a kiss, and then their feelings start developing. Meanwhile, an employee of the same place as Seiji starts growing attached to him too; her name is Risa Ōnuma. As the few love triangles begin interwinding with each other, Seiji begins dating Yuki, but things don't last long well when the horrible past of Yuki comes between them, and the two are forced to break up.
As a result, Seiji is left utterly lonely deep inside, eventually finding Shō as a source of comfort, resulting in the two kissing each other, and later begin dating. Despite the few painful misunderstandings that go on between the two, Seiji later confirms to his first love that he currently loves only Shō, and with that, Seiji has his first time in bed with someone.
Just as Seiji and Shō were both happy to be going out with each other, Shou's ex-boyfriend comes back and asks Shō out once again. This creates some distance in their relationship. Around the same time Yuki's ex-boyfriend Tooru comes back hoping to go out with Yuki once again. Disturbed by this, Seiji wishes he could help Yuki out but found it difficult to do so without hurting Shō. He also finds out Yuki still has feelings for him but supports him and Shō at the same time which starts making Utsumi doubt himself which girl to chose. As a result Seiji choses Yuki over Shō and decides to break-up with her. He later tells Yuki about their break-up which sends Yuki in tears as she supported Utsumi and Shou's happiness with each other.
During a summer-training camp for the tennis club, Yuki asks why Seiji broke up with Shō as she thought she was the reaosn for it. Seiji tells her he did what he wanted and that it is not Yuki's fault. He says he wished to help her out but if he did, it would be rude to Shō. Yuki also talks about Tooru and their history with each other.Later that night one of Yuki's freind comes over to Seiji in middle of the night and says Yuki has gone missing. Worried, Seiji runs off outside hoping to find her and almost breaks into tears thinking of all the possibilites that could have happened to Yuki. During this time he realises his still lingering feelings towards Yuki. He finds Yuki only to find out she was just ringing someone and Yuki tells him even though she does not want to hurt Tooru, she has to be straight forward to him, and Seiji was the one who gave her a courage to do so. Seiji confesses he still likes her. The two hold hands and walk back. After they come back from camp, a few days later, he gets a call from Ryo saying Yuki has gone missing.