An is a close friend of Tomoharu who calls him by his nickname Tomo. Since she also likes him, she always wants him to do things with her.
[Edit]An is a close friend of Tomoharu who calls him by his nickname Tomo. She wanted him to join the club she was in instead of the Science Club. An does finally confess her feelings to him when she invites him as her plus one to the Christmas party. However, he becomes the handler of the Hagane to save Misao and the First World from vanishing and goes to the Second World, preventing him from ever responding to An’s confession.
In the Second World, An confronts him as she is eager to hear his response before Christmas Eve. But, the Tomoharu that she confessed to in the First World will never be able to respond because he died in the Second World. Tomoharu in the Second World feels bad about this so he tells An he will give her an answer later. However, Tomoharu in the Second World and the one from the First World were different people so he answers her by introducing Kanade as his girlfriend.