After listening to the song over and over and watching the live performances
I came to this. Everything else is part in terms to make it easy. It is just
four easy chords. Placed the chords in its original key, but transpose to an
easier key if you like. So I figured the walk-downs and instrumentals, but
the instrumentals are a little tricky and it was the best I could tell apart
from the lead parts and bass riffs. This is how I played it and it made sense
to me.

/ = one beat

Let it Rain
Nichkhun Horvejkul (2PM)

Intro
F#//G#m//A#m//F#/A#m/G#m////C#(strum once and hold for 4 counts)

Verse 1
F# (244322@1)                         C# (x43121@1) Close my eyes and let the world go by
B (x2444x@1)                                D#m (xx4342@1) I feel the rain drops on my mind
F# (244322@1)                                   C# (x43121@1) And when the time goes hard with no where left to hide
B (x2444x@1)                            D#m (xx4342@1) Just wanna drop down and cry

Verse 2
F# (244322@1)                           C# (x43121@1) Then you came and change my life
B (x2444x@1)                             D#m (xx4342@1) Being the bestest friend of mine wooh...
F# (244322@1)                   C# (x43121@1) Oh I can't ask for more
  B (x2444x@1)                     D#m (xx4342@1) So let them bring it on

Chorus
         F# (244322@1) Let it rain
         C# (x43121@1) Let it rain
B (x2444x@1)                    D#m (xx4342@1) Oh I ain't scared no more
         F# (244322@1) Let it rain
         C# (x43121@1) Let it rain
B (x2444x@1)                      D#m (xx4342@1) I know I got you by my side

Instrumental
F#//G#m//A#m//F#/A#m/G#m////C#(strum once and hold for 4 counts)

Verse 3
F# (244322@1)                            C# (x43121@1)  Then you came and change my life
B (x2444x@1)                            D#m (xx4342@1) Being the guardian angel of mine Oh baby...
F# (244322@1)                         C# (x43121@1) Wrap your wings to protect me
B (x2444x@1)                                        D#m (xx4342@1)  Without you I can't make it through the rain

Chorus

(Instrumental opt only if you need to breathe between Chorus and Bridge. If
you want to play an instrumental here, then just play the bridge a couple
times to flow right into it.)

Bridge (play 3 times)
         F#//  
Like an angel
         G#m//
Like my mother
          D#m////                   
Like the bestest friend of mine

Ending
     F#//G#m//
  So I...
D#m////    F#(let it ring out to end)
  Let it rain