One summer day, Hikari, my neighbor on the same floor, was standing in the hallway looking troubled. I greeted her and asked if anything was wrong, and she mentioned her fan wasn't working properly. Out of kindness, I casually offered, "Hey, should I take a look at it?" But then I realized—her husband was away at work. Inside her stuffy apartment building unit, the air was thick with heat. Hikari's blouse hung open, her big tits glistening with sweat. Watching her, I couldn't help but feel a strange, growing excitement.