I thought of this last night.

So in SAO kirito loves asuna but if he chooses sinon. (idk if this happens havnt seen full of SAO saga)

Hanzo and genji could be there offspring.

So another thing is I think kirito taught genji than sinon taught Hanzo this fits.

Also kirito might have taught genji the arcade games in the arcade. 

from this voice interaction from d.va and genji.

source https://overwatch.gamepedia.com/Genji/Quotes

ok maybe not, Sojiro was there father but maybe sinon and kirito where in the same clan.

source https://overwatch.gamepedia.com/Sojiro_Shimada

but this is a theory so idk.