Side Cases are small optional investigations, marked by a blue bubble above a character or a Pokémon. Here are the main ones and their solutions, based on Serebii.

Ducklett.

Chapter 1

  • A lost Lillipup: it is waiting near the fences, in the southwest of the city.
  • The professor’s quiz in Serenity Park: Lickitung south of the park, Purrloin on the terrace, Falinks near the terrace.
  • A soccer partner for a boy in the square: the Raboot in Serenity Park.
  • Ribombee’s Cutiefly: follow their trail with Growlithe.

Chapter 2

  • The clothes of Leavanny’s Swadloon: one near the entrance to the ruins, the other in the Aegislash room.
  • The missing Ursaring: frozen in the Mr. Mime room; Darmanitan frees it.
  • The quiz near the lake: Rowlet, Charjabug and Eldegoss.
  • The hidden Cleffa: near the Passimian, behind rocks near the fossil collector, and near the Lotad pond.
  • The fossil collector: an Armor Fossil and a Skull Fossil, in blocks you break with Darmanitan.

Chapter 3

  • The choir’s Gossifleur: behind a stall in the square and near a flower pot at the police station.
  • A dropped wedding ring between two buildings: a Furret from 2nd Avenue retrieves it.
  • A hungry Pignite: pick Berries from the trees in the square.
  • The quiz: Lilligant and Delcatty near the florist, Hatenna behind the police station.
  • A mysterious cry: a Taillow falls from the tree to the northeast of the square.
  • A stuck balloon: Aipom catches it; a jam jar: Machamp opens it.

Chapter 4

  • Vikavolt versus Heracross: a Sylveon, west of the village, calms them down.
  • The brooch of the Alolan Meowth: near the lake in the bamboo forest.
  • Gumshoos’s curry: a dish for it to taste.