Jishou F-Rank no Oniisama ga Game de Hyouka sareru Gakuen no Chouten ni Kunrin suru Sou desu yo? - Vol. 3 Ch. 18

[MangaDex]

 

[Kuroageha]

The prohibited actions for MC have become ridiculous.

 

[KingRagnarok150]

who texted who about the severer data

 

[Suzukino]

I feel like im stupid, but i stopped understanding this manga a long time ago.

 

[depzdai]

A man of culture would report a handholding picture. Very clever, I see.

 

[Reshfan]

@depzdai
yeah, premarital handholding is a great sin

 

[lionfromnorth]

We know that her family was famous in Black Bouts. We know that her family does not tolerate losers. We know that the MC had been playing Black Bouts for 5 years.

I deduce that the MC defeated her in one of those Black Bouts, that's how he remembers her. That was also the reason why her family disowned her, because they don't tolerate 'losers'.

Just an educated guess.