Renjo Toru is a lonely high school student, and in his class is Aino Ryuti, the most beautiful girl in school.

Golden-haired and blue-eyed, Aino possesses looks comparable to a popular idol and is the daughter of a Finnish zaibatsu. The contrasting pair one day suddenly become engaged by their families' command. What's more, Aino is absolutely thrilled about it.

"From now on, Toru-kun will protect me, right?"

Aino, as it turns out, was actually lonely and timid. Even though they were supposed to be engaged in name only, Aino becomes utterly smitten with Toru...!?

And what's more, the two of them begin living together by their families' command!

"W-we're e-engaged, so... it's only natural for us to kiss, right!?"

This is a story about two people who became engaged in name only, gradually coming to understand each other and becoming genuine lovers.