This is the Chureito Pagoda (忠霊塔) on the grounds of Arakura Sengen Shrine near Fujiyoshida, some 10-odd km northwest of Mt Fuji. It's about a 10 min walk from Shimo-Yoshida Station on the Fuji-Kyuko line, reachable in about 2.5 hours by train from Shinjuku in Tokyo with a transfer at Otsuki:
Note that this view is possible only on a clear spring day during cherry blossom season around mid-April, and Fuji is a notoriously "shy" mountain often covered in clouds, so there are only a few days per year when you can pull off a shot like this. It's also a very well known spot for this, so on those days expect to share the temple with a few thousand Instagram influencers all gunning for it as well.
Random fun fact: this is (at least) the 2nd question we've had so far about the same place!