refactor: use mkdir_p and remove file existance check
refactor: use mkdir_p and remove file existance check

krororo/review,kmuto/review,murashitas/review,masawada/review,kmuto/review,kuad9/review_study,kuad9/review_study,takahashim/review,krororo/review,suzuki/review,orangain/review,orangain/review,kmuto/review,krororo/review,murashitas/review,takahashim/review,masawada/review,suzuki/review