[Ask your E16 question [SPOILERS]]

I need help for a sidequest I think

 

Spoiler

I found a guy near shade's gym, some sort of scientist, he said something about the powerplant and the yureyu Key and "woa u got it, then get inside and do something and I'll just run away" (I was quite sleepy and this is what I Remember). So I get inside the gym and search for something to do but I had already searched the building and there's nothing new. Any hints on what I was supposed ti accomplish??

 

[10TH floor sticker]

U can buy it in 7th street