The firm that saved Eidos believes it will have a return on its 84.3m purchase within three years.
Square Enix Group global president Yoichi Wada has told MCV that the British company is central to its plans to grow sales outside of Japan.
Indeed Wada says his combined group, which also includes video game and coin-op maker Taito, can go on to become the biggest games company in the world.
"Eidos as a company is excellent, with powerful properties and strong management. And by joining our group, we think that the pace of growth and success can now be accelerated," said Wada.
"We would not have taken this decision to buy Eidos unless we thought that we could get our investment back within two to three years. If we had thought it would take five years, for example, then we wouldn't have made the acquisition."
MCV revealed last month that Eidos will continue to operate as usual from Wimbledon, West London for the forseable future.
The deal to purchase Eidos has now been completed, with major IP such as Tomb Raider, Hitman, Kane & Lynch and Deus Ex moving into Japanese ownership.
Eidos-owned studios such as Crystal Dynamics in the US, IO Interactive in Denmark and a Montreal in-house operation will be expected to provide the titles for that Square payback.