Something clicked for me reading 'To Love-Ru' years ago, and I think a lot of the appeal is pure wish-fulfillment fantasy. It’s not even about the titillation for me, honestly, it’s more about the low-stakes emotional safety net. You get a cast of characters orbiting the protagonist, each representing a different archetype or flavor of relationship, but without the crushing pressure of a singular, high-drama romantic plot. It’s comforting in its predictability. The protagonist, often kind of bland, acts as a viewer insert, and the harem setup means there’s always someone new causing a minor, often humorous, conflict. It’s like narrative junk food—you know exactly what you’re getting, a bit of comedy, some mild fanservice, and a sense of being universally desired without the real-world consequences. The ecchi elements are just the spice, not the whole meal.
That said, the better ones do have legitimately fun world-building or a hook beyond the harem. 'The Testament of Sister New Devil' mixes it with demon politics and power scaling, which gives the fanservice scenes a reason to exist beyond just being there. The popularity stems from blending a familiar, gratifying structure with other genre elements anime fans already love, like action or fantasy. It’ With so many options now, it feels like a space where creators can just be silly and indulgent.
Sometimes the sheer absurdity of the situations is the main draw. Watching a guy trip into compromising positions with a dozen different girls, each more powerful or exotic than the last, has a cartoonish charm that pure romance or action series can’t replicate.