Pertaining to something that is immediate or without intermediaries; affecting or relating to something in a straightforward, unmediated way (often used as 'direct' or 'directly').
そのミスは直接的な原因が明らかになっている。
The direct cause of that mistake has been clarified.
彼は問題を直接的に上司に報告した。
He reported the problem directly to his boss.
批判は間接的よりも直接的な表現を好む人もいる。
Some people prefer expressing criticism directly rather than indirectly.