You might find 'Domestic Girlfriend' comparable. It has similar themes of complex romantic dynamics and unexpected plot developments like in World End Harem.
I think 'Redo of Healer' could be somewhat similar. Both have elements of a post-apocalyptic setting and complex relationships.
I think 'That Time I Got Reincarnated as a Slime' might be somewhat similar. It has an interesting fantasy world and diverse characters.
Code Geass might be similar. It has elements of strategic thinking and complex characters like in Deathnote.
The plot of 'Manga Rock End World Harem' involves a post-apocalyptic world on the brink of destruction. A group of characters find themselves in a complex web of relationships within this chaotic setting, with the harem aspect adding an extra layer of drama and intrigue.
I'd recommend 'The Promised Neverland' as it shares some similarities with 'Solo Leving' in terms of its engaging plot and unexpected twists.
You might find 'Starry Night' comparable. Both share similar emotional depth and storylines centered around complex relationships, similar to what you get in 'Wakeari Kiss'.
Well, 'Fruits Basket' could be comparable. Both have engaging storylines that deal with personal growth and human connections. Also, the character development in both is quite captivating.
Yes, there are a few. 'The Gamer' has some similarities in terms of unexpected plot twists and heroic challenges.
Maybe 'Fullmetal Alchemist' comes close. Both have complex worlds and characters facing challenging situations that test their limits.
I think 'Sword Art Online' could be similar. It has elements of mystery and decision-making like in 'Judge and Doubt'.
Perhaps 'Ao Haru Ride' is similar. It has a similar focus on the ups and downs of young love and the challenges characters face in expressing their feelings, much like in 'Forbidden Kiss'.