how to use special utf-8 characters in submodules? - utf-8

Question

Im trying to write my master-degree thesis with latex and that is my first real project with latex, In my thesis I need japanese and some polish characters.
I divided my thesis by submodules. My main module looks like
\documentclass[11pt]{article}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{CJK}
\includeonly{spis_tresci}
\begin{document}
% Definition of title and author
\title{ My Thesis title. }
\author{Mazeryt Freager \\
\\
\begin{CJK*}{UTF8}{min}
一部の日本人のもの
\end{CJK*}
\\ Polish characters are ąćśżźółęń}
\maketitle
\clearpage
\input{Table_of_Contents}
\end{document}
And the above code works perfect.but the problem is in submodule "Table of Contents"
%Also I need utf-8 in file header because Table of Contents include "ś" character in PL
\section{Spis Treści}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{CJK}
%When I add here something more than ASCI code I got into compilation failure
%No mather if it is:
%\begin{CJK*}{UTF8}{min}
%一部の日本人のもの
%\end{CJK*}
%\\ Polish characters are ąćśżźółęń}
abcdefghijklmnoprstuwxyzABCDEFGHIJKLMNOPRSTUWXYZ
%but standard ASCI works
I search a lot about this but I didn't find any solution that works for me

Answer 1

See my answer here on TeX.SX - I'll post it again here for the sake of completeness.
I believe the problem lies in the misconception about the use of the CJK environment - as #egreg said, it can't be enabled and disabled. Just enclose the whole document in one CJK environment and when using CJKutf8 (see here for what difference it makes) utf8 characters using latin script but outside of ASCII will be fine.
Thus your MWE in a fixed version would be:
\documentclass[11pt]{article}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{CJKutf8}
\begin{document}
% Definition of title and author
\begin{CJK*}{UTF8}{min}
\title{My Thesis title.}
\author{Mazeryt Freager\\ \\一部の日本人のもの\\śćóœ}
\maketitle
\clearpage
\input{Table_of_Contents}
\end{CJK*}
\end{document}
with the `Table_of_Contents.tex' having the following contents:
一部の日本人のもの\\
Polish characters are: ąćśżźółęń\\
ASCII: abcdefghijklmnoprstuwxyzABCDEFGHIJKLMNOPRSTUWXYZ
and the output being on the title page:
and
on the first page.