Endovascular coil embolization for intracranial aneurysms, arteriovenous malformations (AVMs), dural arteriovenous fistulas (AVFs), and hypervascular tumors are recognized as an effective adjunctive or curative treatment. In this setting, it is sometimes difficult to navigate a coil delivery microcatheter to the target point of a tiny, tortuous vessel. We herein present a case series of a novel method that enabled super-selective coil embolization using an extremely soft bare, electrodetachable coil (ED extrasoft(®) coil) through a liquid embolic delivery microcatheter (Marathon(®)). The Marathon(®) catheter was successfully placed at the target point of the tiny, tortuous vessel, and coil embolization was achieved in all 16 patients with 9 AVMs, 2 distal aneurysms, 2 AVFs, and 3 meningiomas. The primary ED extrasoft(®) coil and delivery wire have a very small radius, and the coil is rapidly detachable with an alarm notice from the generator even under Marathon(®) with one marker. We believe that this technique can provide safe and efficient embolization for selected patients.