I honestly think it's not because of the grades that Nozomu hates Yuda, he didn't like how close Yuda was to Kiritaka and he was losing his control over Kiritaka because of Yuda, his possession. Yuda also was erasing Nozomu and Kiritaka's history together and taking away Nozomu's sense of power by telling him to turn himself in to the police so he can have his history with Kiritaka back. Yuda was disrespecting him and Kiritaka in Nozomu's twisted perspective.
Instead of bringing up his school grades, he should stick to the reason why he's with Nozomu in the first place, to get revenge for his friend. The joke is getting old already. I think Yuda is pretending to be indifferent towards Nozomu.
I honestly think it's not because of the grades that Nozomu hates Yuda, he didn't like how close Yuda was to Kiritaka and he was losing his control over Kiritaka because of Yuda, his possession. Yuda also was erasing Nozomu and Kiritaka's history together and taking away Nozomu's sense of power by telling him to turn himself in to the police so he can have his history with Kiritaka back. Yuda was disrespecting him and Kiritaka in Nozomu's twisted perspective.