Summary: My youngest brother got into a battle and I showed up late and joined in. After winning it gave me the "Thanks for your help, stranger. We haven't met properly yet, have we? What is your name?" dialog, but it is your brother.
Reproduce: Help youngest brother out in a battle and win. Dialog afterwords will be the below image.
Reproduce: Help youngest brother out in a battle and win. Dialog afterwords will be the below image.