Japanese is not displayed

.pu fille is correctly displayed
but .md file is not correctly displayed

ex) xxx.pu ・・・ correctly displayed
  `  @startuml`
   `a -> あ`
  `@enduml`

ex) zzz.md ・・・not correctly displayed
`  ![aiueo](/root/repository/plantuml/master/xxx.pu)`

