This isn't, technically, complete, but it's as finished as it will get for now. This is because the board is really unfortunately crowded with handwritten messages and it's hard for me to read anything that small and messy. It doesn't detract from the manga very much to have some missing, but I did what I could, so I'm unlikely to add more anytime soon unless anyone actually needs me to or unless someone who also has access to the raws can help out deciphering them.
Ryoma: Is there someone named Tezuka here?
The Princes of That Time
Seigaku Side 1
?: Momo and Kaidou are having their worst fight ever in the clubroom!?
?: This is bad!
?: Heeey, Momo, Kaidou, cut it out!
Everyone: Good job these past three years!
(large) Three years
(circles) Good work
(black) I’ll definitely become stronger too.
(green, higher) Today I’ll do 100 ground shots.
(green, lower) I want to play tennis with you again.
(red) I’ll do my best with Senpai and everyone!
(green) I’m glad I was able to play tennis with you, Senpai!
(purple) We’ll go for two times in a row!
(red, vertical) We’ll definitely win next year too!
(red) We’ll go to Nationals next time too!
(purple) Seigaku will be undefeatable forever!
(black) Thank you, Senpai! It was fun!
(black) You were a great help!
(black) Senpai!! I’m great at tennis!
(purple) Please come play with us sometimes! We’ll get a second victory!
(purple) It’s a new team, but we’ll do our (cut off)
(green) Thanks, Senpai
(purple) I admire you
(red) It’ll be lonely but we’ll do our best! I’m glad I met you!
(green) Senpai! Thank you for everything till now!
?: –And thank you very much.
Ryoma, small: Hehe, huge success.
Tezuka: ...You guys.
Eiji: Heeey~ Ochibi and the others tricked us!!
Taka-san: Whoaaaa, farewell party!!