You can't find that major because that doesn't exist. There is no foreign language major or a major where you just study foreign languages. The closest to that is a linguistics major, which is where you study *parts* of languages, and maybe choose *one* language as a case-study for yourself. Other than that the only foreign language major is majoring in one specific foreign language.
There aren't bilingual entrance exams (exams--not interviews). There are entrance exams in Japanese, and you will not have enough Japanese reading, writing, or spoken knowledge to be able to pass them. So that means knowing all the hiragana, all the katakana, and at least 2,000 kanji on top of adult-level grammar, syntax, and vocabulary.
You're 16. You will not be anywhere NEAR even partially *proficient* (let alone fluent) in less than 2 years when Japanese universities give their entrance examinations.
So you will not be attending a regular university in Japan. You will instead need to attend a university that targets foreign applicants, such as Sophia University, Temple University, AIU, or Kansai Gaidai, to name a quick four. They have classes taught in English, so that is why they are open to foreigners because otherwise you would not be able to write any essays, read any textbooks, or participate in any class discussions.