From Creatures Wikia
Marcus K. which fits nicely with his Konnichiwa Norns. Hanami (cherry blossom viewing) is a popular Japanese event, and this agent causes the left side of the apple tree in the Norn Terrarium to bloom with cherry blossoms. Like real ornamental cherry trees, the blossoms only last a short time, and then fall, covering the area under the tree with pink and white blossoms. But don't worry, the flowers will return to bloom again and again.
This agent is available from the Grendel Warehouse.