Arnold Reks Adler is the seventh prince of the Kingdom of Andrias. While some see him as unmotivated and lacking in talent, he is secretly an SS-rank adventurer known as Silver. Although he is incredibly powerful, what Arnold really desires is for his twin brother, Leonard Reks Adler, to take the throne. However, the other royals won't go down without a fight.
The first thing Arnold does to help Leonard gain the upper hand in the succession is find allies. While most nobles and merchants have sided with the second princess, Zandra; the second prince, Eric; or the third prince, Gordan, Arnold heads to the Duchy of Kleinert. He initially visits as Silver, using the monster outbreaks in the area as an excuse to meet with the family. However, he is turned away at the gate because they refuse to believe that an SS-rank adventurer would show up in their territory.
Arnold then appears as himself and uses illusion magic to arrange a meeting with Silver in front of the duke's daughter, Finne Von Kleinert. They discuss their desire to gain the Kleinert family's support in helping Leonard become the next crown prince. After their conversation, Silver quickly takes care of all the monsters and returns to his room in the duke's residence using teleportation magic. However, Finne is waiting in the room when Arnold takes off his mask. With his identity revealed, he asks her to keep his secret. Finne tells her family that Silver has single-handedly wiped out all the monsters, and she expresses her desire to help Arnold and Leonard moving forward. The duke agrees to support Prince Leonard in the succession and sends Finne to the capital to aid them. Will Arnold be able to maintain his act as an incompetent prince while controlling events from the shadows?
The Insipid Prince's Furtive Grab for the Throne was cool to watch. While the fights aren't particularly long or drawn out, the way the story weaves individual events into a grand plan captivated me. It reminded me a little of The Eminence in Shadow.
There is a shower scene, a bath scene, and a scene in which Elna Von Amsberg and Finne Von Kleinert are shown in their underwear. While I wasn't happy about the unnecessary fan service, I would still recommend giving the anime a try. In my opinion, the story more than makes up for it.