The Summit of the Spire: The Demon-Slaying Heroine

The sword-wielding heroine Angela sealed away Lilith, an evil succubus who bewitched people's hearts. Pleased with herself, she then accidentally walked through a portal to the future.

In an instant, she was in the modern era.

The bewildered heroine looked up at the advertising screens on the skyscrapers and saw that the succubus who had broken free of her seal was selling phones.

Heroine: Huh? I'm going to expose that woman's true nature!

Succubus: Phones. Buy one.

Couple: Angela × Lilith, steadfast heroine × innocent, adorably clueless succubus.

Yuri, 1v1, both inexperienced and faithful, happy ending.

Theme: No one is perfect.