Responses
I think he has two incentives for keeping Janette close:
1) Claude's curse (constant headaches) may only be appeased around Janette. I just know that its the bro's tactic to bring claude and janette together.
2)As revealed in this chapter, he happened to listen in on the familiarity Janette and Athy shared. I bet he's keeping her close to draw out Athy or learn more about her.
From what I can see, he ain't gonna forget her anytime soon. If he isn't awake thinking about Athy, he's either dreaming about her or her mother. ლ(´ڡ`ლ)
Ugh I’m gonna cry if he ends up accepting Janette and just forgets about about Athy ╥﹏╥