Finally, I succeeded to use custom matplotlib Korean font in non-system custom font directory, without installing... thanks https://stackoverflow.com/a/43647344

mpl_notokr.py

# coding: utf-8
# download font from:
# https://noto-website-2.storage.googleapis.com/pkgs/NotoSansCJKkr-hinted.zip
from __future__ import print_function
import sys
import os
import matplotlib as mpl
import matplotlib.font_manager as fm

try:
    _font_notokr_dir = os.path.join(
        os.path.dirname(os.path.realpath(__file__)),
        'Fonts/NotoSansCJKkr-hinted')
except:
    _font_notokr_dir = os.path.join(
        os.path.dirname(os.path.abspath('')),
        'Fonts/NotoSansCJKkr-hinted')

if not os.path.isdir(_font_notokr_dir):
    from subprocess import Popen as popen
    try:
        # python 2
        from urllib import urlretrieve
    except:
        # python 3
        from urllib.request import urlretrieve
    os.makedirs(_font_notokr_dir)
    urlretrieve('https://noto-website-2.storage.googleapis.com/pkgs/NotoSansCJKkr-hinted.zip',_font_notokr_dir+'/NotoSansCJKkr-hinted.zip')
    popen(['unzip','-d',_font_notokr_dir,_font_notokr_dir+'/NotoSansCJKkr-hinted.zip']).wait()
    
fm.fontManager.ttflist.extend(fm.createFontList(fm.findSystemFonts(fontpaths=[_font_notokr_dir])))

_ttfnames = {f.name for f in fm.fontManager.ttflist}
if "Noto Sans Korean" in _ttfnames:
    # mac-OS style
    mpl.rc('font',family="Noto Sans Korean")
    print("mpl font: Noto Sans Korean",file=sys.stderr)
if "Noto Sans CJK KR" in _ttfnames:
    # linux style
    mpl.rc('font',family="Noto Sans CJK KR")
    print("mpl font: Noto Sans CJK KR",file=sys.stderr)