Well, 'Sword Art Online' could be comparable. It features a virtual world and character development similar to what you might expect in 'The World Ens Harem'. There are also adventure and relationship elements.
I think 'That Time I Got Reincarnated as a Slime' might be somewhat similar. It has an interesting fantasy world and diverse characters.
Maybe 'No Game No Life' is similar. It has a unique world setting and complex character interactions like in 'The World Ens Harem'. Plus, the storylines are both engaging and full of surprises.
I think 'Redo of Healer' could be somewhat similar. Both have elements of a post-apocalyptic setting and complex relationships.
One manga that comes to mind is The God of High School. It shares some similarities in terms of action and character development with Eleceed. Both have exciting battles and characters with unique abilities.
One manga that could be similar is 'Fushigi Yuugi'. It has a fantasy setting and complex character relationships like Inuyasha.
I think 'Kuroko's Basketball' is somewhat similar. It has intense sports action and character development like Bluelock.
I think 'Game of Thrones' manga might have some similarities. It has complex character relationships and strategic elements like in Othello.
I think 'Golden Time' is somewhat similar. Both have complex character relationships and emotional developments.
Maybe 'Fullmetal Alchemist' is similar. Both have epic storylines and characters facing significant challenges and moral dilemmas.
You could check out 'Kimi ni Todoke'. Both have sweet and engaging storylines and well-developed characters that draw you in. The focus on emotions and relationships is comparable to Amagami SS.
I think 'The Wizard's Chronicles' could be similar. Both have complex magic systems and characters on epic quests. However, the art style and world-building might differ slightly.
I think 'My Hero Academia' could be somewhat similar. It has action, drama, and diverse characters like Tokyo Revenger.