By Richard Black
Environment correspondent, BBC News website, Japan
How does hunting whales with explosive harpoons square with Buddhism, a belief system perhaps best known for discouraging the killing of animals and encouraging vegetarianism?
Two conflicting concepts of cetaceans exist in Japan today
And how does hunting square with another image of whales, which is also alive and well in Japan - a more western-style vision of friendly creatures to be admired with affection?
These were a couple of the questions I took with me as I embarked on a series about whaling for the BBC's One Planet.
I came face to face with the second contradiction in Ayukawa.
Once a thriving and profitable whaling port, it now carries the faded, rusting air of a town in terminal decline.
At the east end of the strip is Whale Land. When I arrive in fading evening light, the place is deserted.
The most striking feature is an old whaling ship hauled up on dry land, an exhibit for children to clamber over and learn a little of Japan's past, the highlight perhaps being the now defunct harpoon gun on the prow.
But alongside is a series of stone sculptures showing whales as cute, smiley creatures which one might want to cuddle - not kill.
The same apparent contradiction would show up in Tokyo's giant Tsukiji fish market, which claims to be the biggest in the world.
Whilst we chat to staff cutting up red slabs of flesh on a whalemeat stall, my eyes alight on a poster above the stall, where again a cute smiling whale is pictured next to cuts of its meat.
How to make sense of it all? Perhaps, I thought, the past might be a guide.
Spears from the sky
In Nagato, at the southern end of Japan's longest island, Honshu, whaling began in the 1600s. That makes it a newcomer compared with other sites where whale and dolphin remains testify to a history going back about 8,000 years.
Inside the museum, curator Fuminori Fuji shows me a painting depicting boats surrounding a whale.
The hunting method seems amazingly basic, using hand-thrown harpoons. "These you had to throw to the sky," Mr Fuji explains, "so they came down on the whale."
Next to the picture is a collection of ancient harpoons; further along are knives that were used to process the carcass on shore.
Blubber was rendered for oil, bones were ground up for fertiliser, and every part of the meat was cooked and eaten, even the testicles - a marked contrast with profligate westerners who took the oil and threw most of the whales' bodies over the side.
There has been no hunting in Nagato now for a century. Foreign fleets came with more efficient hunting methods; the whales disappeared, and people turned to fishing.
But every year, citizens don traditional clothes and take to the water in traditional boats, ceremonially using traditional harpoons to hunt a "whale" which is made of metal and powered by an outboard motor.
The past evidently dies harder here than in some other places.
Japan has had an unusually close relationship with the sea, a relationship reinforced by Buddhism; and perhaps this is the underpinning of the apparently dichotomous view of whales and whaling.
For long periods of its history, rulers banned on religious grounds the eating of land animals. The sea provided instead, with no distinction made between marine mammals and fish.
In Nagato, there is a highly unusual grave. Inside are whale foetuses, interred in the 17th Century.
"These are the babies of the pregnant mother whales," explains Fuminori Fuji.
"When you process the whales, the babies will still be connected to their mothers; and since the babies could not live on their own even if they were put back in the sea, local people built a tomb for them.
"This grave is facing the ocean, and it's built this way because the babies had never seen the ocean in their lives; maybe after they died they could see it every day."
At the Koganji temple, I am welcomed by the resident monk, Kensai Matsumura.
He shows me plaques recording the names of people who died in the village, complete with the Buddhist names which they were given on their death, providing a way for Buddha to help guide their spirits in their twilight existence.
The plaques also record the names of whales killed, also with Buddhist names.
"This is a whaling town; we've always lived with the sea," he tells me. "We should not forget to thank the whales; that's why we have the tombs, the plaques and the death records."
Koganji belongs to the Jodo sect, one of the four main branches of Buddhism in modern-day Japan.
Jodo monks are allowed to marry, and followers to eat flesh - with restrictions.
As I ask monk Matsumura more about Jodo philosophy, he pulls out a scroll covered in characters which, I gather from my translator, are an archaic and specialised form of Japanese.
"This tells a story concerning Shonin (the founder of the sect)," he relates.
"He was in a fishing village in 1207. A fisherman and his wife approached him and told of their worries, saying 'we live on catching fish and eating them and selling them - would we go to hell after we die?'
"And monk Shonin said, 'if you thank them and give proper service to them, praying for the resting in peace of those fish, then there will be no problem at all'. The husband and wife listened and cried with relief on hearing this."
Modern Japan may have lost the visible trappings of Buddhism which are so obvious in other east Asian countries.
Shrines do not sit colourfully at every street corner, no legions of orange-robed trainees roam the byways as they do in Thailand.
Whale Land: Smiley whales sit in the shadow of a hunting ship
That does not mean teachings and customs have been suppressed or supplanted.
Western observers might not agree with modern Japan's tolerance of whaling, which does not allow the image of iconic, friendly creatures to expel the concept of whales as food.
But Nagato's history and Kensai Matsumura's scrolls perhaps make it a little more comprehensible.