@Lysander ikr... it makes me feel bad when someone accepts a confession just because someone confessed. because that means, no matter who it is, as long as they confessed, they could be his girlfriend. like, what if someone else confesses to Yagyuu? He won't have as much strength to deny the girl who confessed because that's literally the reason why he got together with his current girlfriend.
But I think since Yagyuu is a guy who is serious in those regards, I think he would decline the girl who confessed just because of the reason that he already has a girlfriend. Instead of declining because he has feelings for someone else.
It's nice that he's that nice, but, that could cause serious problems if he never starts to love his current girlfriend, or that he would seriously regret easily agreeing to a relationship when he finds a girl that he would seriously be in love with.