Update 5.5.0 was pushed by Nintendo as a balance and bug-fix patch: Weapon Rebalancing
The file is a compressed archive containing a digital copy of the Japanese version of Splatoon 2 for the Nintendo Switch, packaged as an NSP file with the game's 5.5.0 software update. 🦑 Core File Attributes Splatoon 2 (NSP)(JP)(Update 5.5.0).rar
: Reduced the ink splash radius of far-traveling shots by roughly 5%. Special Weapon Requirements Update 5
: Reduced horizontal and vertical swing ink consumption by roughly 5%. Splatoon 2 (NSP)(JP)(Update 5.5.0).rar