Thanks for your swift response and efforts.
However, it has been noted in the comments section
that the official title is, according to the mangaka, in fact, "Zessyaka!" not "Zesshaka."
Checking more closely myself, I noticed that you can plainly see "Zessyaka" in English above the garage doorway in the original comic by the mangaka, repeated several times in the raws for chapter 4.