"Big Sis! Marry me!"

A bold confession of love, 15 years in the making.

"...Yes."

That confession was rewarded in the most perfect way—with a kiss.
From this moment, the big sister I’ve always loved is now my fiancée.

"Make me happy, okay?"
"I will."

I clasped her small, mismatched hands tightly and nodded with resolve.

We’re both inexperienced, even when it comes to kissing, but together, we’ll learn step by step. Let’s dive deeper and deeper into this sweet, blissful love. Until our awkwardly held hands naturally fit perfectly together—

This is a love story as bright and intense as the summer sun.

[Translated from the official site]