Mochizuki Castle (Koka)




We generally attribute Mochizuki Castle to the leader of the 53 Koka Clans but there is no historical evidence linking the Mochizuki to this specific castle. Mochizuki Castle is one of the largest of the Koka Castles and generally considered to be the most complex and well developed in terms of design. Such developments may have also been the result of helping to defend the Rokkaku giving the above theory more credibility. Mochizuki Castle was also one of the key castles controlling the route into Iga along with Sugitani Castle.

See Castles of Koka for more details

Visit Notes

The main bailey is 65m x 62m with embankments measuring 8.75m wide at the base and up to 9m in high in some places. It's companion castle Mochizukishi Castle is only 50m away across a small valley but is a distinct castle in the yakatajiro design. Mochizukishi Castle is just across a small valley and it should be considered that the two worked together as one fortification. Today it is somewhat difficult to get from one to the other since there is no good path and with thick vegetation to wade through so you might as well go around.

One of my materials from the Koka City has a note glued inside that said that Mochizuki Castle and Mochizukishi Castle are on private property and the owner does not permit strangers on their property. This is probably why there are no signs or trails, unlike most of the other famous Koka castles, and the entrance to each is hard to find. I did not see this before I visited and there are no "no trespassing" signs, but other castle go'ers visit both sites too, so use your best judgment and be respectful.

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Castle Profile
English Name Mochizuki Castle (Koka)
Japanese Name 望月城
Founder Mochizuki clan
Year Founded Muromachi Period (1336-1573)
Castle Type Mountaintop
Castle Condition Ruins only
Historical Period Pre Edo Period
Features trenches
Visitor Information
Access Konan Sta. (Kusatsu Line), 60 min walk
Visitor Information private property
Time Required 50 mins
Location Koka, Shiga Prefecture
Coordinates 34° 55' 9.23" N, 136° 8' 57.70" E
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Collections Koka Castles
Added to Jcastle 2022
Contributor Eric
Admin Year Visited 2022
Admin Visits February 11, 2022
Friends of JCastle
Kojodan - Mochizuki Castle
Jokaku Horoki - Mochizuki Castle
Shirobito - Mochizuki Castle
(2 votes)
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10 months ago
Score 0++

@Eric. Good to see that the wayward samurai residence photos have been put in the right places.

@ART. Not all small castles in Koga have karabori around their baileys. There is a karabori around the massive earthen rampart at Mochizuki Castle, but it’s very shallow when compared to the height of the dorui as Eric has mentioned. The karabori is more akin to a slightly sunken well-worn path between baileys rather than a deep defensive ditch.


10 months ago
Score 0++

This little-known castle ruin in Koga, Shiga has some high earthen ramparts surrounding it. Mochizuki Castle along with Shingushi Castle and Wada Castle, all castle ruins in Koga, have some high earthen ramparts in the 7 to 9 metres range. If you walk along the top of the dorui at Mochizuki and look down the sides, particularly the southern side, it is quite steep, so you know that you are on top of some seriously high dorui.

At Mochizuki Castle, there is one section of dorui ending at the site of the gate leading into the main bailey. This section of dorui was reinforced with some ishgiaki (stone walls). However, the stonewall remnants are difficult to spot as they are now mostly covered by soil and weeds.

I didn’t know that this castle site was on private land, but when I visited, I did notice a couple of people at the little shrine located just outside the main bailey of this castle ruin. To get to this castle ruin, you have to walk through what looks like a vacant block of land, and then up a little path that leads into a forested hill. As Eric has mentioned here, there are no signs warning people not to trespass on private property.

Eric, your photos uploaded here also include photos of Mochizuki Yashiki, which is located somewhere else and not actually at the castle ruin. The Mochizuki Yashiki photos are clearly indicated on the castle profile map at a different location from Mochizuki Castle. Still, you might want to modify your Visit Notes to reflect this. Otherwise, a castle fan using this profile might get the mistaken impression that there are wooden buildings to be seen at Mochizuki Castle.


10 months ago
Score 0++

I also thought that was a little odd. Eric, shall I go through the bukeyashiki pics and 'hide=Yes' them? You're busy and I don't mind.

Also, silly question maybe, but this site also has karabori, right? Neither of your descriptions mention them but with such meaty dorui we'd expect to see that i thought.


10 months ago
Score 0++

Fixed now. Thanks guys!!

@ART - yes there are Karabori but not as much as you might expect given the size of dorui. I think it is must be partially from leveling the areas.


10 months ago
Score 1++
Oh, okay. Sounds like an interesting site. Shinobikonjau naa...