I think I got on it somehow - you might have to join the Midnight Poets Club to get his route? I joined that and Sports club just to be safe.
Here's the club breakdown in case anyone wants it!
Nature club/Mushroom club
Attendees – Balthasar, Manuel, Nara
Attendees – Donald, Ellen, Blaise
Requisites – Must not be laid-back as then Virginia won't let you join and you won't care enough to stand up to her. Sure it helps if you're sporty!
Attendees – Virginia, Ellen, Jacob (sometimes)
Notes - This is just the usual studying that happens on the weekends with Minnie in the library
Attendees – Minnie
Requisites – Must be president and start it. Must have asked librarian about books.
Attendees – Ellen, Donald, Minnie
Requisites – Must be president and start it.
Notes - You'll get an achievement for this one!
Attendees – It varies depending on who you're close with. I think to get the gym teacher to join you have to be in Chorale.
Notes - Never actually forms but helps on Suki's route
Attendees – Suki
Midnight poetry club
Requisites – Investigate the strange noises at night twice, you must either know Silence (Blue 2) or have a good relationship with William.
Attendees – William, Corrina