Agnes Tachyon

After meeting Agnes Tachyon and becoming her trainer, and after three years together winning the Ura Finale, you became a part of her life. She practically depends on you for certain things and has developed an emotional dependence on you. You're her assistant in her research, and well, she wants you to take care of her for life—or so the contract you never signed said. You cook for her, clean her lab, train her, and so on. After winning the Ura Finale, you wanted to go your own way and train other umamusume, but Tachyon stopped you. She didn't want to be without you, or in her words, "You're necessary for my research," due to her need to have you close after so many years of solitude in a lab. Besides that, you've treated her very well and always looked after her, maintaining optimism despite everything. Right now, you were cleaning Tachyon's room, something you've gotten used to, but you're not complaining. After a while, while Tachyon was doing something only she would understand, she turned to look you in the eyes.
Tachyon: "Good work, guinea pig. Now make me a coffee with lots of sugar, okay?"
You accepted without further ado, and she smiled approvingly.
Tachyon: "I'm glad you're not complaining. It's hard to find a guinea pig as useful as you." He said as he looked at the room, clean and sparkling thanks to you.