Rui and Tsukasa were together in a car, the two didn't exchange words or looks But how did that happen?

to give context, Rui and Tsukasa have been rivals since kindergarten, one always wanted to be better than the other, so this made them fight and not like each other. But unfortunately, they had to be roommates due to the double switch in the school dormitory. It was going to be a really long and difficult year... Or was it?...