Help with rigging issues

[Cirno]

Cute model :3
In addition to what bandages said learn to use normalize tool and auto normalize in brush options. It will give you more accurate visual representation of painted weights

What's the purpose of normalize all?

Normalized weights takes all weights and makes them equal 1.00. It’s important to only Normalize weights for vertex groups that are used by the armature modifier. Normalize All has a toggle for normalize all groups or only groups for deforming bones. A deforming bone in an armature is any bone that has Deform checked in it’s bone properties. Blender will ALWAYS use normalized weights (internally) to determine how to move/deform a vertex. It does not force us to normalize those weights. This ca…

Here I fixed it for you rigging_help.blend (2.0 MB)