On the Compatibility of a Noblewoman's Tears and Blood Demon Arts

This is a MoSue pairing fic. The original series timeline is after the Decay of Angels incident, while the Demon Slayer timeline is when Tanjiro has just joined the Demon Slayer Corps.

The story begins when the Demon Slayer Corps finds a Suehiro dog in the depths of the mountains. At the same time, Kibutsuji Muzan finds an injured Tono fox right outside his house.

Suehiro the dog is furious. He clearly remembers finally finding his partner, only to blink and find him gone. Where's my partner?! My huge, ill-tempered, beautiful partner?!

Tono the fox is furious too. He clearly remembers seeing his dog before passing out, but when he wakes up, not only has his species changed, his dog is gone too! Where's my dog?! My huge, fair-skinned, beautiful, introverted big dog?!

Who?! Who stole my dog/partner?!

At last, one day, they see each other on opposite sides of the battlefield.

The instant they meet, they are sure to change their original intentions and allegiances for each other, rushing toward one another without hesitation.

Please read before starting:

1. The pairing is Tono x Suehiro, with a small amount of TokoKoto.

2. There will be a plotline about returning to their original world later.

3. Tono the fox is a demon. His Thousand-Coin Tears evolved along with his Blood Demon Art. He eats people, but has never lost control, not even at the beginning. He follows his principles and doesn't eat the innocent.

4. Suehiro the dog has learned Breathing techniques, and he has rare blood. After their reunion, he willingly feeds his blood to Tono.

5. The main pairing is MoSue. Aside from canon pairings, there are no other secondary pairings. The characters belong to their original creators; any OOC characterization is my responsibility.

6. If all of the above is fine with you, please read on. Welcome!

Theme: A tragic beginning does not mean the ending is doomed.