Yu smiled and brought Naoto by the hand over to a stool in the corner. He pulled down her pants and pulled her over his lap and began to spank her, not hard enough to hurt but hard enough to sting slightly

"Ow!" Naoto squeaked, squirming as she was spanked. Her panties were surprisingly childish.

"Well, that just won't do at all. After your spanking, you should be diapered like a good baby." the shadow said, noticing her real self's choice in underwear.

Yu finished the spanking and rubbed her bottom gently to soothe the stinging, blushing a bit as he did so. He nodded when he heard the shadow's suggestion and took Naoto to the changing table, quite nervous

Naoto followed and hopped onto the table and laid down.

"Have you does this before Yu-kun?" the shadow asked, walking over.

"N-no" he answered, quite nervous at the prospect of seeing his girlfriend's privates for the first time, let alone having to touch them

"Let me help you. I've seen enough videos on how to do it, right little one?" the Shadow teased, getting a diaper and powder at the ready. She took off Naoto's panties and soon had her diapered. "You won't be needing these any more." she said, throwing the panties away.

Naoto blushed heavily, sitting now in only her shirt and a diaper with cute fairy designs based on her Persona.

Yu gulped nervously and looked away with a very visible blush on his cheeks

"Yu-kun, look at me. You said you'd love me no matter what." Naoto said, trying to pull his attention back.

"S-sorry" he said, turning back to face Naoto. He followed the shadow's instructions with shaky hands

Soon, thanks to the Shadow, it was over. "See, it's not hard." the shadow teased. "Now, why don't you two have fun? I'll be over there and waiting for when you need me."