"Until then, if you really like me, I'll go out with you"

When he was in elementary school, Kohei was seriously in love with his childhood friend Tomo-kun, who was a lot older than him. Believing that he will come see him when he grows bigger, Kohei goes to see Tomo for the first time in five years. Although I was shocked to see that Tomo-kun has grown even more, I can't help but feel excited because Tomo-kun has become even more mature.
He wants to become an adult as soon as possible, and as he wishes, an unbelievable and mysterious thing happens...!?And what is Tomo-kun's hidden feeling!?