Hiroki has passed his high school entrance exams, and now he's looking forward to a peaceful, lazy spring vacation before the entrance ceremony. All of that is ruined on the morning he's woken up by Hinata, a stranger who claims to be his childhood friend. The truth is, Hinata is a "tsundere childhood friend" android made for him by his mad scientist neighbors in celebration for him passing his exam! With all the complications his new "childhood friend" is going to cause in his life, what will happen to the peaceful vacation Hiroki had hoped for?