The language requirements for postgraduate research scholarships in Japan are highly dualistic, depending on whether the program and your prospective supervisor's lab environment operate in English or Japanese. The scholarship criteria (especially MEXT) are usually designed to be flexible enough to accommodate both paths.

Major National Scholarship (MEXT Research Student)

1. Scholarship Name: Japanese Government (Monbukagakusho: MEXT) Scholarship (Research Student/Graduate Level)
2. Requirements:
3. English Language: Mandatory. Applicants must submit official scores corresponding to the Common European Framework of Reference for Languages (CEFR) B2 level or higher. This is typically met by scores such as:
4. TOEFL iBT: 72+ (Some university-specific MEXT tracks require 90+)
5. IELTS Academic: 5.5 - 6.0+
6. Alternative: A Medium of Instruction (MOI) certificate stating your previous degree was taught entirely in English is usually accepted as proof of English proficiency.
7. Japanese Language: Not formally required if applying for an English-taught degree/research track. However, applicants must demonstrate a willingness to learn Japanese. If applying to a Japanese-taught track, JLPT N2 or N1 is necessary.
8. Conditions:
9. The MEXT Research Student status is often a non-degree preparatory period (6 months to 2 years) before taking the entrance exam for a Master's or Doctoral degree.
10. If selected via the Embassy Recommendation route, non-Japanese speakers may be required to attend a six-month intensive Japanese language course upon arrival.
11. The ultimate requirement is the approval/acceptance of a supervisor, whose decision often weighs heavily on the language of communication they prefer for research.

Top National Universities (Research Tracks)

1. University Name: The University of Tokyo (UTokyo)
2. Requirements:
3. English Language: Required for admission to all international graduate programs. For the Graduate School of Science (a common MEXT destination), the minimum is often TOEFL iBT 72 / IELTS 5.5 (CEFR B2 equivalent), though competitive applicants score much higher (90+ / 6.5+).
4. Japanese Language: JLPT N1 is essential for most traditional and humanities-based graduate schools where research is conducted in Japanese. It is not required for the numerous English-only programs.
5. Conditions:
6. Many Graduate Schools (e.g., Engineering, Science, Public Policy) offer English-only tracks (e.g., International Programs) for both Master's and PhD, where the primary language requirement for admission and scholarship is English.

1. University Name: Kyoto University
2. Requirements:
3. English Language: Mandatory. For English-taught PhD programs, a strong score is expected, often IELTS 7.0 or TOEFL iBT 90+, to demonstrate readiness for advanced academic writing and seminars.
4. Japanese Language: JLPT N1 is the requirement for all research conducted outside of the dedicated international English programs.
5. Conditions:
6. Kyoto University has a growing number of English-Taught Degree Programs (Master's and PhD) across its schools, where English proficiency is the sole language barrier. Scholarship nominations (MEXT/university-specific) are often integrated into the application process for these English tracks.

1. University Name: Osaka University
2. Requirements:
3. English Language: Required for their international programs, usually set at IELTS 6.0-6.5 or TOEFL iBT 80-90.
4. Japanese Language: Not required for admission to their English-taught PhD programs (e.g., in Engineering, Science).
5. Conditions:
6. Osaka University places a high value on the supervisor's decision and the quality of the research proposal. If the supervisor agrees to conduct all research communication in English, meeting the minimum English test score is sufficient for the scholarship application.

1. University Name: Tokyo Institute of Technology (Tokyo Tech)
2. Requirements:
3. English Language: Mandatory for the International Graduate Program (IGP). The requirement is high, typically IELTS 6.5 or TOEFL iBT 90+, reflecting its research-intensive focus.
4. Japanese Language: Not required for admission through IGP.
5. Conditions:
6. Tokyo Tech is highly selective. Its scholarships (including MEXT University Recommendation) are tied directly to admission to the IGP, making high English proficiency and a stellar academic/research background the primary focus.

1. University Name: Tohoku University
2. Requirements:
3. English Language: Required for the Future Global Leaders (FGL) programs. Competitive research applicants typically aim for IELTS 7.0 or TOEFL iBT 95+.
4. Japanese Language: Not required for their PhD programs taught in English.
5. Conditions:
6. Tohoku University has a robust system for English-based research. Meeting the high English standard is key to securing MEXT or the university's internal scholarships.

1. University Name: Nagoya University
2. Requirements:
3. English Language: Required for the Global 30 (G30) Master’s and Doctoral programs: IELTS 6.0 / TOEFL iBT 80+.
4. Japanese Language: Not required for G30.
5. Conditions:
6. The university’s emphasis is on international research collaboration. Scholarships like the MEXT-G30 track require a proven record of English proficiency and a compelling research plan.

1. University Name: Kyushu University
2. Requirements:
3. English Language: Required for their International Graduate Programs. Minimum scores are generally IELTS 6.0-6.5 or TOEFL iBT 80+.
4. Japanese Language: Not required for English tracks.
5. Conditions:
6. Kyushu often uses the MEXT Scholarship to recruit research talent into specific, high-priority research fields. The language requirement is strictly enforced to ensure effective communication in the lab.

1. University Name: Hokkaido University
2. Requirements:
3. English Language: Mandatory for English-taught graduate programs; competitive applicants typically have IELTS 6.5 or TOEFL iBT 90+.
4. Japanese Language: Not required for admission to the English research programs.
5. Conditions:
6. For MEXT University Recommendation, the research focus and the compatibility of the applicant's language skills with the supervisor's lab culture are major deciding factors.

1. University Name: Waseda University (Private)
2. Requirements:
3. English Language: High proficiency is required for international PhD programs (e.g., Graduate School of Advanced Science and Engineering). Scores often align with the highest national university standards: IELTS 7.0 or TOEFL iBT 100+.
4. Japanese Language: Required for traditional research programs.
5. Conditions:
6. Scholarship applicants (including those nominated for MEXT) must satisfy both the general MEXT requirements and the specific, often higher, English requirements of Waseda's graduate schools.

1. University Name: Keio University (Private)
2. Requirements:
3. English Language: High proficiency is essential for research scholarships in the Graduate School of Media and Governance (GSM) and other international schools: IELTS 6.5-7.0 or TOEFL iBT 90-100.
4. Japanese Language: Required for traditional Japanese-taught research programs.
5. Conditions:
6. Keio's selection is highly competitive. Having a strong research proposal coupled with outstanding English proficiency is key to receiving a scholarship recommendation.