I want to know what Makoto wanted Chiaki to do. I bet it would have been something that Chiaki would have enjoyed, like eating leftover cake from a party.
I can't find anything about Coharu Sakuraba ever having published a manga called
Suiyou Doudeshou (How Do You Like Wednesday?), which was also the name of a
comedic travel TV show which aired from 1998 to 2005, but I suppose it could have been a doujinshi (just meaning self-published, not necessarily anything erotic) that was only distributed at Comiket or somewhere like that.