Ako and Hiro were always together. Ako was so sure that Hiro reciprocated her feelings, but after he rejected her, it left a deep scar in her heart. Ten years have passed since then. Ako decides she needs to spread her wings and forget all about what happened. Right when she's having trouble convincing her dad to let her move out on her own, someone comes to the door. It turns out to be Hiro, her first love, and they haven't seen each other since the rejection. But, since Ako's parents trust him a lot, they let her move into his apartment building. Ako is thrilled to be on her own, but when she forgets to call the gas company, she's forced to ask Hiro for help and close the distance between them. Ako wants to reset the bittersweet memories of her first love and try her relationship with Hiro again.
「私…あなたが…好き」「……ごめん」
ずっと一緒にいて、私だけは特別で、紘（ひろ）もそう思ってくれていたと思っていたのに…。
勝手に勘違いしていたのは私だけど、その事が私の心に深い傷跡を残している…。
あれから10年、あの時の事は思い出さないように胸に仕舞い込んで、私は新たな人生を歩もうとしていた。
そう！憧れの一人暮らしを！と言うことで父親を説得していたら、突然誰かが訪ねて来た。
それは、10年ぶりに再会する私の初恋相手の紘だった…。
両親の信頼が厚い紘と同じマンションならと言う条件で無事（？）一人暮らしを始める事になったけど、いきなりのアクシデント発生で仕方なく紘を頼る事に…。
苦くて甘かった初恋の思い出…。
リセットして、もう一度あなたに…。