Atomでコンパイルしようとしたらエラーが
でるんだけどこれってどういうこと？
pLaTeX2eって記述がちゃんとしてるのにthis is LateX2eに
なってしまうのはなんででしょうか?logにはこのように記述されています。

This is pdfTeX, Version 3.14159265-2.6-1.40.16 (TeX Live 2016/W32TeX/dev) (preloaded format=pdflatex 2015.11.21) 24 DEC 2015 23:00
entering extended mode
restricted \write18 enabled.
file:line:error style messages enabled.
%&-line parsing enabled.
**./test_japanese.tex
(./test_japanese.tex
LaTeX2e <2015/10/01> patch level 2
Babel <3.9m> and hyphenation patterns for 79 languages loaded.
(c:/w32tex/share/texmf-dist/tex/platex/jsclasses/jsarticle.cls

c:/w32tex/share/texmf-dist/tex/platex/jsclasses/jsarticle.cls:38: LaTeX Error: This file needs format `pLaTeX2e'
but this is `LaTeX2e'.

See the LaTeX manual or LaTeX Companion for explanation.
Type H <return> for immediate help.
...

l.38 \NeedsTeXFormat{pLaTeX2e}

The current input file will not be processed further,
because it was written for some other flavor of TeX.
You're in trouble here. Try typing <return> to proceed.
If that doesn't work, type X <return> to quit.

長文失礼いたしました。