Why?!

Easy

Bird Song
Does crime pay?
Erupting Helplessness
Traffic Jam in Tokyo
When I see candies.

Medium

Burial Anthem
Hail Mary
John and an Animal
Kidnapped Sweetheart
Morning Daredevil
The One Who Murdered the Suicide
Peace in Flames
Thank heavens!
An Unfortunate Favor

Hard

Deadly Naivety
A Deadly Traveler
Dismissed Call
Life-Saving Spit
Saved by the Weather
A Sunday Jumper
Tropical Danger

Very Hard

The Frost Messenger
The Ingrate