Those two met by chance and Taitou was kinda rude to Chigusa but Chigusa didn´t care at all.
Chigusa is a bright and cheerful Person afraid of getting into a relationship and refuses any confession. It´s because his father cheats repeatedly on his mother and ever since she found out she became mentally unstable. She often beats him up but Chigusa just lets it happen. Not even his cousin who goes to the same school knows about their situation.
Taitou is someone who is feared by girls easily due to his stature and the fact he won´t smile. He seems like a guy who ridicules everyone and doesn´t care about anyone. He has trust-issues and can´t express himself properly with words most of the time. He only has two friends but those he treasures. Later on he really falls in love with Chigusa.