In the beginning they were both very cold to each other, but later on they slowly opened up to one another. There were hints that they both liked each other such as Mafuyu getting jealous over other girls and Sasha always being protective of her. Before Sasha leaves, they go on a date and it ends with both of them giving each other their first kiss. In the beginning, Sasha did not give importance to Mafuyu, calling her flat-chested. But after Mafuyu's breasts begin to grow and he spends more time with her, Sasha starts paying more attention to her and starts taking a liking to her. This attraction soon grows into love.
Tomo reminds Sasha of his deceased sister Olga, thus it causes him to seek to protect her at all costs.