Writing Japanese blog with Ghost

I have just migrated my blog from WordPress to Ghost. The reason is that it is just at the beginning of the year and I have been interested in something new. Ghost Foundation, which has been developing Ghost, seemed to gather certain amount of fund via Kickstarter. The headquarters are in Singapore, which sounds super to me.
Strange display in Japanese
I have noticed, just after deploying the instance on a local machine, that the layout of the default theme Casper is obviously wrong.
Then, I have modified the theme so that it fits Japanese.
Modified version of default theme Casper for Japanese
This is the modified version.
The modified theme is available on Github repository. https://github.com/inatus/Casper-ja