Hachimitsu to Clover Photo-Making Book Cover

Here's the cover of the "Hachimitsu to Clover" Photo-Making Book which is essentially a pictorial book on the production of the real-life movie. I have yet to get this book yet so a proper review of this will only be available once Kinokuniya has it in their stores. Judging from the attire which the five main characters are wearing, I get the impression that they must have gone to a place where they need to wear black formal clothing. Could that be a funeral? However, there's no funeral in the manga/anime so this is purely my conjecture. Otherwise, I don't see why the colour scheme of their clothing is on the dark side where this is too much of a coincidence if there wasn't any special occasion. By the way, Morita i.e. Iseya Yuusuke looks kind of weird in a formal suit although Shinobu does wear flashy ones for his enka performances during the spring hanami sessions.