The help wasn't pointless. He just lied when he said he was going to make sure Tojoin doesn't interfere. In reality, he went to make sure Tojoin doesn't interfere too early in the date or stop the date altogether. His involvement had messed up a few plot elements from the source material he had read in his previous life, and he wanted to be there to make sure that he didn't f*** the romcom's plot beyond all salvation. He also gets to go on a date with Sei-chan, so there's that too.So... the "help" was pointless. Man had one job, and he decided he'd rather do the opposite.