Happy-Go-Lucky Days is a Japanese manga series by Takako Shimura. It was serialized in Ohta Publishing's manga magazine Manga Erotics F from 2002 to 2004 and was collected in two large-sized tankōbon volumes. The manga is a collection of short episodes that depict slightly eccentric love stories and mundane daily life in a matter-of-fact manner with a unique tempo and delicate psychological descriptions. Most of the episodes in the collection have direct sexual depictions, although they are drawn in a light-hearted way. The manga's title comes from the book Herahera Botchan by Kō Machida.