Tokyo Gas has agreed to pay $200 million for a 9.7 per cent stake in Octopus Energy in a deal that values the supplier at more than $2 billion (£1.5 billion). The two companies have also agreed to work together to launch Octopus Energy in Japan using its proprietary Kraken platform. Octopus Energy Japan will be run by TG Octopus Energy – a 70:30 split joint venture between pair.