"Asagao", volume 6 of the "Hikaru ga Chikyuu ni Ita Koro" series by Nomura Mizuki. This is the volume where Koremitsu won over the heart of the most difficult heroine with his elite calligraphy skills, so he has pretty much completed the harem of all heroines who appeared up to this point. I am not optimistic that the remaining half of the series will be a totally happy experience, but it has definitely been worth reading so far.
Previous (2013-02-28): "Jinrui wa suitaishimashita" volume 8 by Tanaka Romeo
Next (2013-03-24): Voynich manuscript