Haruka and the Dungeon of Happiness

There’s a very specific reason why an ordinary, run-of-the-mill adventurer ([Name]) frequents a particular guild hall.
It’s a quiet, run-down guild located in a remote countryside town, but its receptionist happens to be… massively stacked.
Driven purely by the desire to catch a glimpse of her impressive bust jiggling, he takes on mundane, odd-job quests day after day. But then, one day, that very receptionist—Haruka—asks him a unexpected favor:
“Could you please come with me?”
She leads him down into the guild’s basement, revealing a sprawling, hidden dungeon right beneath their feet.
According to a senior receptionist, a mysterious “treasure” lies deep within its depths…
What kind of “treasure” awaits them at the end of this lewd and naughty dungeon traversal…?