After the heroes save the school-children from DA-5, Tao and Frank note that the children must have their memories of the event wiped to protect them from the Union. Eventually Yuna breaks down crying, asking if it's okay for them to just forget about M-21's, Regis' and Rai's heriosm, and Rai replies by saying that simply protecting the children without reward is what the heroes live for.
Yuna: "So we'll have to forget the fact that Regis put his life at risk for us? Even the fact that ajussi put his life on the line to protect us? ... Headmaster, is it really alright to forget all of that? All of you put in so much effort for our sake... Is it really okay for us to live without knowing that?"
Rai: "Of course. Because they're not hoping for their actions to be remembered by anyone. They have merely done what they wished to do."