In an interview with Polygon (Link), Fire Emblem Heroes Director at Nintendo, Shingo Matsuhita, addresses the game’s more risqué approach to character art, especially for the summer swimsuit events.

In the interview, Matsuhita acknowledges the game’s generally mature audience and that it was not Fire Emblem’s first foray into Swimsuit art.

Polygon: Some of the character art, especially during the summer swimsuit events, has been pretty risque for Nintendo, which is traditionally known as being family-friendly. How do you decide what’s appropriate for the artwork in the game?

Shingo Matsushita: If you look at the Fire Emblem series since Awakening, we’ve had DLC that involved characters in swimsuits. So this isn’t exactly a new concept. And, as you mentioned, Nintendo does have a family-friendly image. But within all of Nintendo’s franchises, Fire Emblem is generally played by people that are a little bit older. So when we make games for this series, we keep that in mind.
It’s not that we’re making heroes in swimsuits just to have swimsuits. Fire Emblem Heroes is a game with a lot of deep strategy and gameplay, but at the same time there are a lot of great characters, so we want to give back to the fans a little bit of fan service. This is something we’ve had a positive reaction to in the previous games. So when it came time for Fire Emblem Heroes, the development team really wanted to include that as well.
We’re also talking about the design. When we’re thinking about the design for these characters, we’re definitely trying to be very careful about it. One thing you could say [is], we’re trying to maintain the dignity of these characters that we love. If you think about Fire Emblem characters, a lot of times they can be very serious, a lot of times they’re fighting, but sometimes it’s very nice to let the characters hang loose a little bit and let their hair down.

While Intelligent Systems does not seem to have any problem with inserting “suggestive contents” in their games, they have faced some criticisms and difficulties with them, especially during western localisations due to cultural differences. It is good to see that they’re always working hard to strike the perfect balance.