Hello. Thanks for mapping.
You mapped here, 
https://www.openstreetmap.org/way/1423983724/history#map=19/31.743243/130.695452
7 buildings, despite it is 1 building with 2 roof parts, and a round storage tanks
The lowest objects are car parks. 
you also included the front wall into your mapping. Just map over the rooflines and move the whole to the footprint.
This link shows large buildings, but the idea is the same

Check this page to see what I changed.
https://overpass-api.de/achavi/?changeset=170815240
Best regards
