Usage patterns
〈組織〉の士気が上がるfor a group's morale to rise
The victory raised the team's morale.
士気を高めるto boost morale
The coach spoke to the players to boost their morale.
士気が低下するfor morale to decline
Long hours of overtime caused employee morale to decline.
士気を保つto keep up morale
Even in tough conditions, the unit kept up its morale.
士気が高いmorale is high
This team has high morale.