They should've focused more on Mashiki and Mishima from the very start, instead of focusing on Mihashi and Honda. The other characters introduced earlier barely have significant impact on either the story or the characters' development.

The picture book is cute and the story itself is wholesome. However, this episode feels pretty weak for a finale... If you really enjoy cliche high school romance, then this anime is passable. If you don't, I'd just say skip it.