Maybe 'Kiss Him, Not Me' would be comparable. It has a touch of secrecy and unique class settings. The characters and their relationships might give you a similar feel as Secret Classes.
It has an engaging plot and unique characters. The art style is also quite appealing.
I think 'To Love-Ru' might be somewhat similar. It has elements of romance and comedy like Secret Class.
Well, Secret Classes comics often have a combination of mystery, drama, and maybe a touch of romance. The characters' development is a key focus, and the plots tend to keep you on the edge of your seat. The art can vary from detailed to more stylized, depending on the creator's style.
It's unique in its own way. It has distinct story elements and character developments that set it apart from many others.
Often, similar manga have comparable art styles, maybe with detailed backgrounds and dynamic fight scenes. The story pacing and plot twists could also have some similarities. For example, both could have unexpected alliances or betrayals.
One manga that comes to mind is 'Your Lie in April'. It has a similar emotional depth and explores complex relationships.
I'd suggest 'The Promised Neverland'. Both have unique storylines and characters that deal with hidden secrets and supernatural elements. The art styles are also somewhat comparable.
I'd recommend 'The Breaker' as it has a similar blend of action and drama like Secret Class.