Some people here are saying shit like "it doesn't make sense" and "gege used all the tricks in his book" like the twist from this chapter was a shounen trope! And if you want realism, don't read battle shounen. Read a slice of life.
Is the MC stupid or did he take classes for it? Who the fuck follows a random stranger into their home after they offered you to live there with them?!?! (╯°Д °)╯╧╧
But I like that the MC doesn't take it lightly, he knows that the ML is a psycho