The box had been entirely Michiru's idea, of course, but Haruka had more than gone along with it. She knew that being so far from home made it all too easy to get homesick, and that things like this... well, they tended to ease things off a little.
"It's not like we're exactly ones to judge when it comes to childish. We did once have a water balloon fight to settle an argument." And Haruka had lost! Terribly!