A consortium of Japanese automakers is pitching what it calls an investment opportunity to help build a future based on hydrogen fuel cell vehicles. Initial outlays will likely be huge and returns are a big question mark. Payoffs will likely come a decade down the road, if at all. Even one of the organizers calls it “high risk.” But a group of the country’s automakers and energy companies is going ahead with the new company to jump-start construction of a hydrogen refueling network across Japan. The idea is to share startup costs and bring in outside investors interested in a piece of the future. The consortium of 11 companies — including Toyota, Honda and Nissan — announced their venture last week, saying they will pool resources to build 80 hydrogen stations in the next four years.