Grace Klaus (Not her real name) was an old friend and crush of Sage Wainwright. She was Sage's first real love when they were close friends in Elementary school until he started to get to clingy for her liking. She's one of the inspirations for Amai Tenshi.
Grace and Sage went to the same school and they were basically soulmates. However, as time passed, Grace started becoming friends with other people and Sage started to get super jealous and started taking her for granted. It especially didn't help that in their later years in elementary school they started being in separate classes. Grace started to dislike Sage and accused him of being a stalker and a creep. There's a difference between being a stalker and caring about your friend, he's never followed her home, he never spied on her but he was kind of goofy around her because he hadn't really had fully developed social skills like other people had.
Sage have tried several times to make thing up to her and to have her give him another chance but she kept calling Sage a stalker and even started blaming his behavior on my mom since her mom knew her. (Why Amai treats Seji like shit from time to time.)
Since Sage was homeschooled, he started visiting his old friends at their middle school but he never walked up to Grace once, and even told other people that he didn't really care much for her anymore. (which was sort of a lie.) But the final day he met with my old friends, he said goodbye for the last time to all of them... and Grace smiled at him... not a mockingly smile of a stereotypical mean girl... but a smile of affection... he chose to ignore her and when he got into the car... Grace's spirit dropped.
He never found out if Grace felt bad for how she treated him as kids, and even though Sage am mostly over her and he would only want to be friends if she came back. (He has two new crushes but one don't know me since he met that one online, DON'T WORRY, THEY'RE REAL PEOPLE!!!!) But he would've sill drop everything he has in his hands to be there for someone he love, maybe if they did emotionally scar him. That's basically what Seji did, which is why Sage hate him so much. He hate the fact that he has more strength to still put up with Amai's bullshit than Sage did with Grace. I know, jealous of an Easter egg character you made... pathetic, right?
Sage hasn't been in love with anyone else for over four years until he met my new crushes online. Even though we haven't met in person, I still feel loved when I talk to them or think about them, but they're a secret for now!
Sage's advice for you all is: When you fall in love with someone, don't ever take them for granted. Just show that you'd take a bullet for them.