This article is more than 1 year old

This article is more than 1 year old

Two bonsai enthusiasts in Japan have pleaded for the safe return of seven trees worth tens of thousands of pounds that were stolen from outside their home.

Seiji Iimura, a fifth-generation bonsai cultivator, and his wife, Fuyumi, alerted police last month after the miniature trees went missing from their garden in Saitama, near Tokyo.

They included a 400-year-old shimpaku juniper – a variety prized by collectors that is worth at least 6m yen (£42,000), according to the Asahi Shimbun.

It appears the thieves had the expertise to target the most expensive tree among the 3,000 the couple keep on display in their 5,000 sq metre garden, which is open to visitors.

Iimura described the stolen trees as “household treasures”, while Fuyumi said they had raised them “like our children”.

“I am filled with sadness and heartache,” she wrote on Facebook.

Bonsai, or the art of delicately sculpting small trees, has gained a worldwide following. Japan exported about 12bn yen’s-worth of trees, bonsai and potted flowers last year, up from 4.5bn yen about a decade ago, according to the agriculture ministry.

Fuyumi had one request for the thieves: ensure that they water the shimpaku juniper regularly. “The shimpaku lived for 400 years. It needs care and can’t survive a week without water,” she told CNN. “It can live forever, even after we’re gone. I want whoever took it to make sure that it’s properly watered.”

Jack Sustic, the curator of the bonsai museum at the US National Arboretum in Washington, likened the theft to “someone stealing your beloved cat or dog, and you don’t know what they’re doing with them. It’s a terrible thing.”

Sustic told the BBC World Service: “You certainly develop a connection with bonsai trees over the years, taking care of them on a daily basis. They are hardy, but if you don’t water them for three or four days, or even a day in some cases in the hot summertime … they could die.”