A crossover anime/manga series, starting with Kaguya's fiancé.

Lynn transmigrated to the world of Danma, obtained a proficiency system, gained abilities, grinded proficiency, and participated in lotteries. As long as he worked hard, becoming a god was not a dream.
By a twist of fate, he became Kaguya's fiancé.
Since that's the case, let's get married first!
Lynn naturally joined the Astrea Familia.
What? Kaguya doesn't want to! Let's beat her up first.
What? No feelings? No worries, a beating is a sign of affection, scolding is a sign of love. Hit me first, then love me. Hit me every day and we'll develop feelings.
Kaguya: Lynn, why are you holding that stupid elf's hand? I'm the first wife!
Ryu: Lynn, don't do that, someone will see us.
Alexandra: Justice tells me to follow my heart. Lynn, let's become sworn brothers?
Laila, Maru, and others all expressed that everyone should have their own opinion: Kaguya is the eldest sister in the inner quarters, but outside, she is Yamato Rindou Kaguya.
Artemis: If you can pull my gun out, you are my love, and I will follow you no matter which world we are in.
Many years later, facing numerous lovers, Lynn, supporting her aching back, still recalled that distant afternoon when she saved people in the Far East.