Ichinichisanshoku Doujin Title. It is spelled with Kanji for one, day, product, and touch. It might also be noted that the second and third of those Kanji taken together are the same as those used to spell "Nissan". There may be some deeper meaning or pun in this that I'm completely missing.

*shiver*

Rie, the elder sister with a mania for tentacles.

Eri, plaything who is growing cold.