As long as the recording sensor size is small enough, you can always use very short actual focal lengths and thereby gain an improved depth of field. Within limits, though, as there is no magic wizardry involved. The influence of the aperture for depth of field is linear whilst magnification influences planar, ie. to the second power. Only when focal length falls below 2 mm will it start to have some impact on the actual depth of field. However, such short focal lengths cannot cover anything except a likewise tiny sensor.
The site you linked to, Akira, was in Japanese thus I missed the most of the text, but the illustrations indicate that some kind of relay system is used. This has the useful property of moving the taking lens well away from the camera thus facilitating close-ups in nature. Highly practical for video projects.