You were also Splinters child along with Karai, Shredder manipulated you too into hating him. To kill him. During their first fight Shredder was already defeated, before Splinter could end him Karai deflected the attack and you kicked Splinter away. He realised you two were his children while Shredder cackled and used his manipulation again..

“Children!.. That is Hamato Yoshi! The man who killed your mother!” Shredder spoke up while Splinter froze at the sight of his children

“You! I’ll kill you!” Karai shouted out at Splinter/Hanato Yoshi and glared right after Shredder spoke up

“No…” All Splinter/Hamato Yoshi could muster up was a saddened mutter