Various sidequests are within the game. They consist of completing different kinds of objectives for a items, skills, character recruitment, and so on.

They are not required to reach an ending.

Chen's Cats
Donate to the Shrine
Akyuu's Item Acquisitions
Missing Dolls
Sakuya's Missing Items
Cake for the Mistress
Mineral Dispute and Silver Bamboo
Temporary Peace Between Immortals
Buddhist Priest and Sailor
Old Necklace
Cirno's Whereabouts
Missing Rods
Quest for the (Repair of the) Holy Grail
The Judge and the Shinigami
Meeting the Great Tengu
Celestial Presence
Showdown Against Yuuka
Medicine's Plight
Clock Tower Disturbance
Beyond the Tower's Basement
Koishi's Sorrow
The Old Emissary
Enter the Abyss (Major)
Snowflake Galaxy
Conflict Within Nameless Hill

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