Aka wrote:
Gamu wrote:
According to the Hepburn romanization, "ヅ" must be written "Zu".
i heard that nowadays people don't use "ヅ" anymore to express "zu" but "ズ". is it wrong? cause im really curious 
In the Nihonshiki romanization which Japanese people use when typing with their keyboards, it's correct.
However, the method of romanization which osu! uses is the (modified) Hepburn romanisation as it has been stated into the Ranking Criteria, in which both ズ and ヅ is expressed as "zu" as Gamu's screenshot says.
= Japanese characters are expressed as their actual pronunciations in the Hepburn one. e.g. を=o, は(particle)=wa, へ(particle)=e
Probably this made you guys having lots of knowledge of Japanese confused.