Tantyyellow

This theme's featured function is "Posts sorting" by using custom template. You can filter posts by category, tag, and date. Also, you can change the order by date, post's name, etc. What's more, it has foldable "Sidebar," so you can hide it to focus on content and open it only when necessary. This theme is designed as much as simple, so you can start a blog right away. In addition, this is customized for use of Japanese. Of course, this is responsive.