Humanity Has Declined Season 1 Episode 9

The Fairies' Survival Skills

After an increase in fairy population leads to bullying, the heroine is sent to accompany asylum seeking fairies to find a new home for them. Through various circumstances, the heroine ends up stranded on an island in the middle of the ocean, along with a group of pessimistic fairies who declare her the queen of their new nation. The fairies' motivation to work on building their new nation soon increases their population. The nation soon evolves into a bustling civilization dedicated to serving its queen, who begins living in luxury. Upon cultivating a plant that can produce candy, the fairies' research and development soon turn the nation into a literal candy island. However, after a lapse in judgment causes everyone to build monuments everywhere, the island is soon ruined and devoid of food and water, sending it into poverty. The heroine feels they should leave the island, but remains trapped by a rainstorm caused by the collective depression of the fairies.