Well, 'Konosuba: God's Blessing on this Wonderful World!' is a must - mention. Kazuma is reincarnated in a fantasy world and teams up with a group of misfits, including some female characters who form a sort of harem around him. It's known for its humor and unique take on the isekai genre with harem elements.
The key features of this manga include an otherworldly setting, a charming protagonist, and a group of diverse and attractive characters forming the harem. The plot might have quests, battles, and emotional entanglements. The art often enhances the immersive experience with its colors and designs.
One popular one is 'The Rising of the Shield Hero'. It features a unique isekai setting where the protagonist is summoned to another world as the Shield Hero, and gradually forms a harem of diverse characters throughout his adventures.
One popular harem isekai light novel is 'In Another World with My Smartphone'. The protagonist is transported to a fantasy world with his smartphone and soon finds himself surrounded by various female characters. Another is 'Overlord', where the main character, Momonga, is trapped in a game world and has interactions with different female npcs that could be considered part of a harem - like situation. And 'The Rising of the Shield Hero' also has elements of harem isekai, with the main character, Naofumi, gradually gathering a group of female companions during his adventures in the isekai world.
One popular 'isekai harem novel' is 'No Game No Life'. In this story, the two main characters are transported to a different world filled with games and rules. They encounter various female characters, and a harem - like dynamic develops as these characters are drawn to the protagonists' intelligence and unique abilities.
If you're new to isekai harem light novels, start with 'No Game No Life'. It has an interesting concept and the harem aspect is more about the relationships based on the game - playing. 'High School DxD' is also a popular choice, but it has some more mature themes, so be aware. However, the story is exciting and the harem is a big part of the plot.
Love and relationships are also key themes. The development of relationships between the protagonist and the members of the harem can range from simple friendship to deep romantic love. These relationships often face challenges, like jealousy among the harem members or external threats to the group, which adds drama to the story.
The following are some recommendations for the reincarnated imperial harem novels (completed):
1. "Reborn Concubine: My Beloved Concubine Is Not to Be Trifled With": In this ancient romance novel, the protagonist became a favored concubine after her rebirth. She used this to dominate the harem and suppress those who bullied her.
2. "Female Supporting Harem Promotion": The author's sister loves dresses. It tells the story of a female lead who became a queen from a cannon fodder female supporting character.
3. "Harem Making a Living": The author's sister loves dresses. It's a sci-fi space-time travel novel. The female protagonist also unfolds her story in the harem.
Please note that the novels recommended above are all completed works.
I'm not sure about its popularity. It might be popular within the niche of isekai and harem - loving audiences, but it may not be as well - known to a broader readership.