1,18 again (Mistake)

Edit:  1.Legally Romance

 Inkling:

1,18 again

This one doesn't count because he doesn't time travel, he only becomes young.

 NoirRoseHeart:

This one doesn't count because he doesn't time travel, he only becomes young.

whoops you are right.i will edit when i think of one.

2. Lovely Runner

3. Go Back Couple

4. 365: Repeat the Year - hope, 1 year younger also count here

5. The Princess Royal

6. Familiar Wife 

7.  Marry My Husband

8.  Somehow 18

10. Summer in Love

Someone else can pick 

10 titles with a "only one person can do this to him/her" trope

Like an ability not a boundary

1. I'm Not A Robot - ML is allergic to humans and only FL can touch him

It has been a while since I watched but

2. Sm:)e

3. A Breeze of Love (Ml has insomnia but he’s able to sleep in the presence of the other  ML)

4. Color Rush (ML can only see colors with the help of the other ML)

5. Your Sensibility My Destiny (ml has no emotions or senses, only fl can help him have these abilities)

6. Love Me Like I Do  ML faints when he sees the color red and FL is his cure.

7. Go into your heart - ML is total colorblind, FL is the only person he can see color on, like the entire of her body is colorful for him.

8. Love Me in Three Days - when ML touch someone body more than 5 second he become that person, usually he need to wait until three days to get back to himself, but with FL's kiss he immediately back to himself

9. La Pluie - They hear each other thoughts on rainy days