Both movies that include a mother who has passed away coming down from heaven to spend a short time with her child. They both seem quite healing but tinged with sadness.

Both have a fml who's dedicated entirely to her study as it's her second chance to do better at the Gaokao.
The fml helps motivate the ml who's not that interested in studying hard anymore. Both the mls also have a career as a pilot.
A Ray Of Light doesn't have much romance compared to Don't Disturb My Study but they both show a snippet of the future after graduating where the couple in DDMS get together while the one in ROL leave it open ended.

Alchemy of Souls and Princess Agents both have a really strong female lead who because of some circumstances goes under another identity as the ml servant. Although in Princess Agents the ml was already strong and was re-training the fl who had amnesia, in Alchemy of Souls the fl whose soul transferred into a weak body is the one training the weak ml.