Yahoo Japan, NTT Docomo, Credit Saison and Colopl joined existing investors Gree, GMO and Fidelity International to fund Japan-based Kaizen's series B round.

US-based user experience optimisation platform Kaizen Platform has raised $8m in a series B round backed by a raft of corporate investors.

The new investors in the round were YJ Capital, NTT Docomo Ventures and Saison Ventures, the respective corporate venturing subsidiaries of internet company Yahoo Japan, mobile network NTT Docomo and payment services firm Credit Saison, as well as mobile game developer Colopl.

GMO Venture Partners, the corporate venturing arm of internet company GMO; Gree Ventures, which fulfils the…