I'm curious on what is Satoru's real name... Is it Wachi or Daisuke??? or is Wachi his nic...

Wachi is his last name and Satoru is his first name. Daisuke is a mistranslation.

Japanese names (As well as Korean and Chinese names) are usually in 'Last name First name order' (For example, Makio Hijiri is Last name/ first name).

Japanese people also refer to each other mainly by their last names because calling people by their first names is a sign of closeness. (Japanese people usually get called their first names by family members or close friends)

So Makio was pretty intimate with him at the beginning and called him Satoru but at the later part of the manga, he starts calling him Wachi.....

Ah, wait, my mistake. I messed up. Satoru and Wachi are the ones that got mixed up in translation. Wachi's full name is Wachi Daisuke. (Satoru is incorrect translation while Wachi is the correct name)