The Vinculum Gate (羈絆門, Kihanmon) is a strange, extradimensional location in killer7. Entry to the Gate is controlled by the Gatekeeper, who will only allow the Smith Syndicate to pass if they give him the requisite number of Soul Shells. The precise number of shells needed to access the Gate varies with each scenario, ranging from anything between 1 and 7.
Each of the killer7's visits to the Vinculum Gate follows a pattern; upon entering a seemingly ordinary door somewhere during the Target they are instead transported to the Gateman's lobby, a small room with a black-and-white checkered floor and several couches. The Gateman, who stands behind a window similar to a bank service desk, will take the killer7's Soul Shells and unlock the double doors to the right.
Behind the door is a small corridor that leads up a flight of stairs to the Colosseum, a vast, empty octagonal hall dotted with various pieces of wreckage. In the centre of the Colosseum stands a small structure, although access is blocked by a shutted door. On each of the Colosseum's 8 sides there is a door; entry to the hall is through the door on the east side, whilst the remaining 7 doors all lead to different areas depending on the Scenario.
These areas are often strange, warped versions of locations within the real world; for instance, the Gate area accessed in Sunset Part One is the approach to Toru Fukushima's private quarters at the back of Restaurant Fukushima, although the area is entirely shaded in tones of light grey and white, giving it a rather surreal, otherworldly feel. Other areas, such as the Coburn Elementary School library in Smile Part Two and the basement morgue beneath the Blackburn Residence swimming pool in Encounter Part Two, are relatively normal-looking. The 'real' version of the areas are not accessible once the player has completed the Vinculum Gate.
Before going through the door to each Gate area the remnant psyche of Kess BloodySunday will appear to give the killer7 hints on defeating the special Heaven Smile within. These special Smiles vary dramatically; some appear later on as regular enemies whilst others make their only appearance within the Gate. If they manage to reach the killer7 their explosion is nearly always instantly fatal, no matter how much health the player may have. The one exception to this is the Galactic Tomahawk Smile, which shoots missiles at the Smiths rather than exploding.
After defeating the Smiles the door at the back of each Gate area leads to the Gateman's room, through the small door on the left-hand side. The killer7 then proceed through the big double doors to the left of Gateman's kiosk, down another flight of stairs and then back into the 'real' world.
It is revealed in the final scenario, Lion, that the Colosseum is in fact an old, dilapidated structure located on Battleship Island. Its location on Japanese-owned territory, as well as Iwazaru's suggestion that the Gateman is in league with Kun Lan, reinforces the idea that the Vinculum Gate is specifically designed to hamper and slow down the killer7, as well as suggesting that new, deadlier varieties of Heaven Smiles are sometimes tested on the island before being mass-deployed. During the scenario Emir Parkreiner accesses the small hut in the middle of the Colosseum and finds a staircase leading to an underground tunnel where Kenjiro Matsuoka is waiting for him.
This is a list of each Vinculum Gate area and the unique variety of Heaven Smile located inside:
|Target||Soul Shells||Colosseum Door||Location||Heaven Smile|
|Angel||2||SW||"Celtic" Building||Speed Smile|
|Sunset Part 1||1||SE||Restaurant Fukushima||Phantom Smile|
|Sunset Part 2||4||N||KAKU building||Backside Smile|
|Encounter Part 1||3||S||ISZK-LAND||Mithril Smile|
|Encounter Part 2||3||NW||Blackburn Residence||Laser Smile|
|Smile Part 1||7||W||Union Hotel||Timer Smile|
|Smile Part 2||1||NE||Coburn Elementary School||Galactic Tomahawk Smile|