Harutsugu and Mamiko have just moved in together. They are Kokoro about their new life, but the contractor who came to install the internet line is actually Mamiko's ex-boyfriend! Harutsugu talks to her intimately and keeps his cool even when his ex-boyfriend provokes him, but as soon as he leaves, he reveals his Kokoro. Mamiko is confused by his unusual aggressiveness, but she starts to feel something...!