Crossover: The Childhood Friend I Let Grow Wild

She is a mischievous childhood friend. He is a proud, tsundere childhood friend. She has a strange bloodline and keeps reincarnating in different worlds. He pursues her relentlessly, yet always loses track of her. In the end… He says, "I'm tired. I'm done chasing you. When you're finished playing around, get back here and make me dinner, or I'll bite you to death!" She says, "No way! You stinky sparrow, if you don't come find me, I'm not coming back!" Companions, friends, elders, family. Along the way, she gains a lot and loses some things, too. Longing, bonds, affection, obsessions. Along the way, he comes to understand a lot and gains a lot, too. It's basically the long, winding love story of a tsundere sparrow and a fierce, adorable girl. The whole thing is meant to be gloriously chaotic, so no fact-checking, please!