Tsugou no Ii Kimi

Not every person can be happy about having a boyfriend that works as host. Katsuzou is one of those that have something against. To express it he throws at Tomosa (his love interest) a dunno_what_is_that (smth looking like a small fire extinguisher xD). Luckily, it didn't killed Tomosa but it seems like he has lost his memory... What in that case will Katsuzou do?
(from B-U)