After many years of absence from Japan, what is the first thing Naoto does when he comes back? He goes back to his old orphanage to bring gifts to the children. And as soon as he finds out of their plight, he pays their debts with the money he owes to Tiger's Cave, fully knowing he's risking his life.
Naoto always helping orphaned children, and never taking a reward for it.
Tiger's Cave doesn't forgive one of their wrestlers not paying his dues, so they send Mr. X to check on him. Mr. X comes... And, upon learning why Naoto was late with the payments, gives him one last chance. Considering that the one wrestler who had tried to talk down the dues had died a horrible death, that's quite the soft spot Mr. X has for the children.
Related to this, Mr. X fully knows this is Naoto's one weak spot, but he never targets the orphanage in the anime. And in the manga he does it only when he'd otherwise die and is desperate, and actually intended to let Kenta go once Tiger Mask was dealt with.
One anime-only Tiger's Cave wrestler has the same soft spot, to the point he refuses to use illegal moves in his match with Tiger Mask upon learning why he had deserted.
When Naoto learns that the Yakuza the orphanage owed money to still want more money to settle the debt and have the law on their side, he pays the rest of the debt... Fully knowing that this way he would blow his last chance to settle his debt with Tiger's Cave, and this time Mr. X would summon the assassins.
The reason Tiger Mask starts fighting as a face: Kenta had escaped the orphanage and was there during his match with Black Pyton, Tiger's Cave first assassin, and declared he wanted to become strong, tough and bad like him, when Ruriko, knowing Kenta, arrived to take him back and asked him to show Kenta a better way. Tiger Mask says nothing... And frees Black Pyton from the ring ropes before fighting him without fouls, and winning. And while the public thinks he did it for publicity, Kenta realizes what Tiger Mask wanted to make him understand.
Tiger Mask's action with Gorilla Man, who had been Raised by Gorillas before Tiger's Cave took him in and thus is closer to a beat than a man, refusing to take advantage when he makes a hole in the ring and gets stuck-instead taking him out of the hole-and then, after defeating him, making sure he could rejoin society.
Anime-only character Daigo Daimon is one of Tiger's Cave trainers... And a friend of Naoto, who refuses to fight him and has to be forced. He later becomes an ally until his death against Tiger's Cave admins.
When Mr. X organizes the World Maskmen League and dares Tiger's Cave to enter their tournament, Tiger Mask does it... Because otherwise he couldn't pay the operation to restore the eyes of a blind girl.
In the same tournament Naoto at first fights without fouls and finds himself at the mercy of Mister No, the weakest of Mr. X's wrestlers. What does make him fight back with fouls? A phone call by Kenta pointing out that in a no-rules tournaments fouls were legal: he had been holding back because he didn't want to give Kenta a bad example.
Meta: in 2010 and 2011 many children's homes and other social welfare centers received donations signed "Naoto Date".