Conversation so far:
what was Jikken Kobo?
an artistic group established for multidisciplinary collaboration on mixed-media projects, who sought to avoid Japanese artistic tradition.
what kind of projects did they produce?
During this period he wrote Saegirarenai Kyusoku I ("Uninterrupted Rest I", 1952: a piano work, without a regular rhythmic pulse or barlines).
what else did he produce?
by 1955 Takemitsu had begun to use electronic tape-recording techniques in such works as Relief Statique (1955) and Vocalism A*I (1956).
was he working on his own or did he get help from others?
Takemitsu also studied in the early 1950s with the composer Fumio Hayasaka, perhaps best known for the scores he wrote for films.
What films did he write for?
films by Kenji Mizoguchi and Akira Kurosawa, the latter of whom Takemitsu would collaborate with decades later.
did he get any awards for his music?
CANNOTANSWER.
what genre of music did his productions have?
his Requiem for string orchestra (1957  listen ), written as an homage to Hayasaka, was heard by Igor Stravinsky in 1958 during his visit to Japan.

Question: what year did the early development start?
Self-contained rewrite: What year did Tōru Takemitsu's early development start?