Suguru's journal name is a reference to one of his canon nicknames-Last Five Seconds Miracle Fighter. Because he always loses, right until the last 5 seconds, then he wins.

nevergiveitback is a bit more complicated. Kuroro is from a place called Meteor City, which is actually a country sized junkyard. The country is a SCARY place and they look after their own. So when someone from the city was falsely arrested, out of spite, the 32 people who were involved in the case were killed in suicide bombings, leaving notes saying 'we accept everything, so never try to take it back.' As Kuroro is the Quintessence of Theft, and on the other end of the equation being a Meteor City resident, I reversed it.