> Is this mansion if from that hata other manga?
This is Nagi's mansion from Hayate the Combat Butler.
> in two months: they got maried, moved togheter, their house burned down, moved to a public bath house, met tsukasa's sister, went to the amusement park, went on a trip, went camping, nasa started working as a teacher, and a lot of other things i forgot... HOW THE FUCK
Yep. Not uncommon. In Hayate the Combat Butler, there was more of an emphasis to remind the reader that even though a ton of time had passed in reality, only a small amount of time had passed in the manga. That element has been missing from Tonikaku Cawaii.
When Tsukasa returned to Nasa's life, that's when the clock starts. They immediately get married that night. And pretty much every new day that happens is pretty much "the next day" in world. So to get everything in that they've done in 2 months is quite easily doable.
The only thing that's a stretch is the rapid reconstruction of their apartment building. I get that the Japanese can move very fast when they want to. But two months is kind of a stretch, considering all things that go into building something, including the bureaucracy. Is it possible? Yes. But it is a stretch to me.