We Should Have Slept While Only Holding Hands, And Yet?! - Volume 01

My childhood friend who lived next door since preschool, Ja Saeyeon. On the outside, she appears like an adequately pretty girl who’s like a drawing, but only her body has grown; she was a girl whose mental age was truly that of an elementary schooler. We’d spend time together from time to time, but Saeyeon’s parents, who were often not home, would pay me to take care of her, so we merely had a ‘work’ relationship. But this time her spoiled behavior was more severe for some reason. She fretfully asked for me to sleep together with her since she was too scared to sleep by herself. I even sang her a lullaby, but she thought that I was going to run away so, with great care, she asked if we could sleep while holding hands. We then slept together. Really, seriously, we merely slept while only holding hands.
But the next morning⎯⎯⎯there was a young girl lying down between us?!