Four minutes and thirty-five seconds into the video, the final two members of the group can be seen running across a field towards the camera, and disappear out of frame just as the tsunami is snapping at their heels. One of them made it to safety despite having broken a bone in her foot as she was climbing over her garden wall, and by an incredible stroke of luck, the other - who only gets around with the aid of a walking stick - was scooped up by a floating rooftop and deposited on the hillside without injury.
Although it's hard to make out, on the left-hand side of the screen from around the five-minute mark, some residents from a nearby old people's home are in the process of being rescued - you can get a slightly clearer view two and a half minutes into this next video, shot from almost the same location.
When he was interviewed for the documentary, Daichi - who was just ninteteen years old at the time, and with his chubby features, acne and pudding-bowl haircut is probably the least heroic looking young man I have ever seen - recalled the events as follows:
'I thought that either I was going to abandon Umeko and run away, or we were going to die together. Of course, when I looked into Umeko's eyes, I thought, "If I let go of her hand now, I may regret it for the rest of my life". I thought of her as a member of my own family.'
Daichi pushed Umeko to safety, and out of sight of the video camera, even the man who is apparently washed away as this is happening somehow managed to scramble his way back onto dry land.
Umeko was interviewed for the documentary along with Daichi, and said, 'Daichi is like a grandson. He is so kind, and he really saved me when I was sitting in that wheelchair.'
Just as I was wiping a tear from my eye and wondering whether Daichi has been given some kind of award for this incredible act of bravery, Mrs M turned to me and said, 'If that was me I would have left her behind. She's ninety-four - she's lived enough already, hasn't she?'
Oh well, so much for sentimentality.