Designer Rio Kobayashi has created a London Design Festival "living room" filled with objects he created with the help of artist and designer friends.

Manus Manum Lavat is the first solo exhibition from the Japanese designer who trained as a cabinet-maker in Austria before setting up his studio in London in 2017.

Presented at LDF venue Cromwell Place from 16 to 24 September, the show featured new and never-seen-before works including a multi-coloured modular sofa and a dining table with a tuna fish painted on top.

Kobayashi said his aim was to show how friendship plays an important role in his work.

This responds directly to the theme of this year's Brompton Design District, set by curator Jane Withers, which is Conviviality – The Art of Living Together.

"When Jane told me the theme, I thought it was perfect for my exhibition," Kobayashi told Dezeen.

"I wanted to create a living room, a place where people could feel comfortable, and then swamp it with works I made with friends."

The exhibition title alludes to this. Manus Manum Lavat is a Latin phrase meaning "one hand washes the other".

"It means working towards something together for common benefit," Kobayashi explained. "I really like the expression because, after Covid, it feels a bit cheeky."

The show centres around the Piece of Cake Sofa and the Fatty Tuna dining table.

Fatty Tuna is a collaboration with artist James Hague, who often creates paintings of fish. Kobayashi had the idea to turn the fish into a four-legged creature, featuring a shark fin that doubles as a serving board.

Piece of Cake Sofa, created with designer Flavia Brändle, is a playfully reconfigurable design.

The upholstery features a textile by fashion label Peter Pilotto, which had its own exhibition in the room next door. In exchange, Kobayashi helped the brand create a trio of lighting designs.

"We wanted to be convivial by mixing together," the designer said.

Two works in the show were created by creatively repairing old, broken pieces of furniture.

The first, created during the pandemic, is a vintage Thonet chair that has been updated with carved markings, a colourful woven seat and a backrest that looks like a broom.

The second is a transformation of a table that had been stored in an attic for many years. This led Kobayashi to turn the piece upside down, creating a shelf that resembles a bat.

"That's why I hung it so high," he said.

Music was key to creating a relaxed atmosphere for the show, while allowing Kobayashi to present his new collection for Austrian audio brand Wiener Lautsprecher Manufaktur.

Totem-like speakers and a zigzag-shaped amplifier feature colourful graphic patterns, produced using marquetry craft techniques.

The many other works in the show included lantern-style lamps, kinetic bird mobiles, an intricate partition screen crafted from cedar wood and Japanese paper, and a stool from Kobayashi's first-ever design collection, Mikado.

"It's here as a reflection on my starting point," he said.

There were also a couple of references to the show's title. A hat emblazoned with the Latin words hung from a custom-designed wall hook, while hand-shaped soaps were presented on antique plates.

These plates were sourced by designer Bethan Laura Wood, who nominated Kobayashi for the Design Museum's Ralph Saltzman Prize earlier this year.

"There are so many stories," Kobayashi said. "But it's easy to tell those stories when they are about friends."

Manus Manum Lavat was part of Brompton Design District, which was on show from 16 to 24 September for London Design Festival. See Dezeen Events Guide for more architecture and design events around the world.