In The Sunroom

In December of 1970 Takemiya published a short story, "In the Sunroom" (in Bessatsu Shojo Komikku) which is possibly the first shonen-ai manga published and contains the earliest known male-male kiss in shōjo manga.

The manga volume consists of five shorter stories:

• Sunroom Nite (In the Sunroom, 1970)
• Hohoemu Shounen (The Laughing Boy, 1972)
• 20 no Hiru to Yoru (20 Days and 20 Nights, 1973)
• Star! (1974)
• Mister no Kotori (The Mr.'s Baby Bird, 1975)

Source: MangaUpdates