When I realized this was a manga series available through my library, I just put a hold on the first two volumes, because why not. I think this one included more episodes that I was unfamiliar with, since they weren't adapted for the anime. The developing misunderstanding of Yokoi's and Seki's relationship by Goto is amusing. I think in the anime it came up in just one episode, but it appears to a recurring theme in the manga, so I will probably read more.
Also, I love the font and back covers showing Seki goofing off; this one with the murder-mystery investigation and reveal of a hidden passage is especially entertaining.