Re-direct to English Site

Hi Support,

I have 2 languages for my site (English and Japanese). I have set my English site as one page scrolling on homepage, example, when clicked on “About Us’ on the menu bar, it will scroll down to “About Us’ section on homepage and when clicked “Our Products” on the menu bar, it will scroll down to “Our Products” section. It is working well on English site but on Japanese site, when I clicked the menu bar, it direct to the English site.

Please advise how can i make the Japanese site same as the English site, many thanks.

The page I need help with: [log in to see the link]