|Age||11 or 12|
|Relationship to Lain||Crush|
|Relationship to Touko||None|
|Cause of Disappearance||Moved away|
Tomo (トモ Tomo), affectionately called Tomo-kun by Lain, is a boy in Lain's class in Elementary school in the game. While he and Lain were not close, it is implied that they may have had a mutual crush on each other, although it was never requited.
Not much is known about his personality, but it was stated in Lain's Diary that he and the other boys in her class were very rowdy.
Relationship With Lain
Lain often seems to think about him and worries what he thinks of her, especially when she has trouble fitting in with her peers and when she is bullied. It appears she may have had a crush on him, although it seems that she was too shy to approach him. When Lain falls ill with influenza, Tomo and Lain's teacher pay her a surprise visit, much to Lain's embarrassment. However, Lain is unable to speak to Tomo, preoccupied with her teacher. The two of them exchange a handshake before parting ways.
When Lain returns to school, she discovers that Tomo has moved away before she could say goodbye to him, upsetting her. However, soon after, Lain receives a series of brief letters from him, to which she enthusiastically replies. It appears that eventually Tomo stops writing her, leaving Lain heartbroken. Her interest in him eventually fades.
Effect on Lain's Mental Health
Tomo is a large source of self-doubt for Lain, and she often worries about him laughing at her and whether or not he actually cares about her. After he moves away, Lain becomes preoccupied with the fear that Tomo is not exclusively writing letters to her, but instead just the whole class as a nice gesture, and becomes obsessed with the notion of being "special" only to him, hoping that he was writing only to her and thinking about her. These fears are groundless, however; the Serial Experiments Lain Official Guide states that Tomo was in fact writing exclusively to her and also could possibly have been interested in her as well.
After his letters stop coming, she mentions that she think school would be happier if she could have gone out with him, and wishes she could transfer to his school. She eventually gives up on the idea.
Her unrequited interest in Tomo may have been responsible for the later appearance of Misato.