Urawa Reds are wasting no time retooling for next season, announcing the signings of forwards Rafael Silva and Ado Onaiwu on Wednesday.
Despite finishing at the top of the overall table, Urawa again missed out on the J. League championship, losing to Kashima Antlers on away goals in the two-legged final last week.
Reds, who captured the league cup this season, have not won the league title since 2006.
One of the best finishers in the league, Silva helped keep Albirex in J1 as Niigata fought off relegation by goal difference over Nagoya Grampus. The Brazilian scored 11 goals in 23 games.
The 21-year-old Onaiwu has spent his entire career in the second division with JEF United Chiba. The player with mixed Japanese-Nigerian parentage just missed the cut for Japan's Rio Olympic team, for which he was a backup.