A more realistic scenario for healthier sleep could still get you there due to the ~15 fast levels around the end of the 60 levels.
First lessons: 7am, d0
L1A1: 11am, d0
L1A2: 7pm, d0
L1A3: 6pm, d1
L1A4 + Second lessons: 5pm, d3
L2A1: 9pm, d3
L2A2: 5am -> 7am, d4
L2A3: 6am -> 7am, d5
L2A4 + First new lessons of next level: 6am -> 7am, d7
However, doing this will just take up so much time and energy, it would be much healthier not to. I’m currently on a small break from lessons right now due to overwhelming circumstances, inside and outside WaniKani.
EDIT: Didn’t mean to make that a reply to Belthazar