That wasn't MTL, it was a fully lucid choice on my part🐱
I admit that Young Lady might have been a bit weird, but ultimately I thought it was acceptable for the moment... In any case, leaving it at onee-san or translating it into older sister was ruled out at first.
I had a slight suspicion of this while translating the chapter! Since it had been years since I touched a beyblade, I was sure I wouldn't catch all the references (especially the part with the beyblades lined up... They really area all the same). Honestly, I only translated the chapter to see if...