Lagrange: The Flower of Rin-ne

While Yoko sends her assistant to search the ocean floor for an unknown object, Madoka-still struggling to control Midori-returns to Kamogawa to celebrate the New Year. Back home, she gets letters from Lan and Muginami, sharing updates about their lives, and quickly writes back. Time passes, Madoka advances to the next grade, and Lan and Muginami explore a space-themed replica of Kamogawa on the tourist destination Polyhedron. This story unfolds between the first and second seasons.