Looking for a roommate, I visited the address listed on a flyer and ended up moving in with Hotaru Yamakawa, who lived alone. Hotaru is kind and always considerate, making my days feel comfortable and pleasant. However, I constantly find my attention drawn to her presence, leaving me with little private time. Especially the sight of her underwear peeking out from piles of laundry, or her voluptuous thighs hidden beneath a short skirt, makes my heart race every single day. Then one day, I accidentally caught her masturbating in the bathroom. After that moment, I could no longer hold back—my desires became impossible to control.