Everyone gets sick sometimes. That's normal. When Nishijima gets sick, though, he gets sick like nobody's business; fever, chills, the works.
It's not like it takes that much effort for Hidaka to pick up a lot of new games and DVDs, so that Nishijima can newborn calf-wobble out to the couch with his blankets and they can set up home there with them for the day, but he figures he might like it. It reminds him of that time when he was in school when the girl he had a crush on caught the measles and he went and read to her every night after soccer practice, even though his mother and his sister scolded him that he was going to get sick himself.
He finds himself telling Shuta that story for some reason while he cadges a ride with him over to Nishijima's place.
"You really liked this chick, then, huh?" Shuta says, in a neutral tone, when he's through.
Hidaka stares out of the window. "Yeah. I was crazy about her."
He's still looking away when the lights change again and they pull off, or he'd have asked Shuta what that frigging smirk on his face was about.