Japanese Public Information Symbol - "Emergency exit" symbol. Same symbol is used in <a href="https://en.wikipedia.org/wiki/ISO_7010" class="extiw" title="w:ISO 7010">ISO 7010</a>, however this version is a different shade of green, per Japanese standards.
<a href="//commons.wikimedia.org/wiki/User:Alerante" class="mw-redirect" title="User:Alerante">alerante</a>, based on PDF linked above
<a rel="nofollow" class="external text" href="http://www.ecomo.or.jp/sym_win_english/p15.pdf">Symbols-Safety</a>, <a rel="nofollow" class="external text" href="http://www.ecomo.or.jp/">Foundation for Promoting Personal Mobility and Ecological Transportation</a>, abbreviated as the Eco-Mo Foundation