Film and TV Crossover: Nainai's Journey to Make Dreams Come True

What kind of story unfolds when a brand-new character appears in a TV or film series?

No angst from beginning to end, just a sweet, indulgent Mary Sue story.

Detective Conan, paired with Gin (on hiatus)

Reply 1988, paired with Kim Jung-hwan (complete)

My Date with a Vampire 1, paired with Yamamoto Kazuo (complete)

Ode to Joy, paired with Zhao Qiping (ongoing)

Feel free to leave a comment if there's anything else you'd like to see!

Please show me lots of support!