Corporate Vision


Basic Management Policy

We have evolved our business mainly of oil refinery maintenance and construction since our establishment in 1988. 


We have supported our customers’ business activities to their full satisfaction and made solid achievements with solid reliance, sophisticated skills and technology in the wide range of business including shipping agency, and shipping and receiving agency service of petroleum products.


We have utilized our human resources of abundant knowledge and sophisticated experience in the field of oil refinery maintenance and engineering work which are our superiority. 


We carry out our Management Policy below and aim for a company which contribute to safe development of the local communities with our stable and best effort through daily business activities.


1. Safety, Human Health, and Environmental Protection are our top priorities which are our basis of business management. Compliance with laws and further highly sensed moral values are our foundation of business activities.


2. We contribute to improvement of our customers’ satisfaction by offering our refined skills and technique of maintenance and engineering, quality and service.


3. We foster full-grown social business persons on the basis of spirits of taking care of “people”.


We contribute to the local communities’ development with social reliance for an ever-lasting company. 

Company Overview

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Nanseki Kaihatsu K.K.


April 1, 1988


Paid-in Capital ¥ 30 million (Shares Issued: 1,600)


Main Office:1498 Aza-Onaha Nishihara-Town, Okinawa

Chubu Office:7-18 Suzaki, Uruma-City, Okinawa


President and Representative Director, Hitoshi Oshiro


42 (As of July, 2019)


Representative Director : Hiroshi Higa

Managing Director : Hiroaki Miyagi

Director : Hisaka Furugen

Director : Akira Tokashiki

Director : Yukio Ikemiya


Approval from Okinawa Prefectural Governor

:(General-24) 6857

Construction、Electric Work、

Plumbing、Equipment Installation 、Fire Defense Equipment 


Approval from Okinawa Prefectural Governor

: (Special-24) 6857

Civil Engineering, Scaffolding, Masonry Work

Steel Structure Construction, Pavement Construction

Coating Work, Water Utility Construction

Demolition Work


Bank of Okinawa/ Nishihara-Branch

Bank of The Ryukyus/ Nishihara-Branch

Scope of Business

Ⅰ Construction and modification of plant facilities of petroleum, petrochemical and LGS.

Modification, Repair, Maintenance and Operation assistance. 

Ⅱ Civil, Architectural, Structural, Electric, Piping, and Mechanical instrument installation work

Maintenance and Construction of Fire protection facilities.

Ⅲ Sales of Commercial Lubricant

Ⅳ Shipping Agent Business


April 1, 1988

June 16, 2000

March 22, 2014

September 1, 2014

Nanseki Kaihatsu (NSK) was established as a a subsidiary company of Nansei Sekiyu.

Was in charge of the whole contract works of maintenance in Nansei Sekiyu.


Became an independent company.


The main office moved to NISHIHARA Kogyo Danchi (Industrial Park).

NSK's new office is equipped with a workshop with a ceiling crane and a warehouse on the third floor.

Opened two spacious material yards near the main office and functionality of the shop was improved.


Opened a Chubu office with a workshop in Suzaki Uruma City due to an increase in construction orders in Chubu area.

The Chubu office is working as a hub of construction on U.S. bases and Japan's Self-Defense Forces facilities.

Qualified Employees(As of May, 2017)

Class-1 Civil Engineering Works Execution Managing Engineer : 3


Class-1 Electrical Work Operation and Management Engineer : 1


Electrical Work Engineer (First/Second type) : 7


Boiler Expert : 3
Boiler Maintenance Technician :6

Hazardous Materials Specialist : 26


Production Safety Management Chief of High Pressure Gas(Chemical Machinery) : 5


Operations Chief of Organic Solvent : 5


Operations Chief of Specified Chemical Substances : 2


Fire Defense Equipment Officer : 3


Education of Foreman/ Safety and Health Controller : 11


Class-1 Health Officer : 2


Construction Quality Management for

contractors : 2


Chief Engineer of Water Supply Equipment Construction :1

Chief Engineer of Sewer Drainage Equipment Construction :1

Class-1 Building Operation and Management Engineer : 1


Second-Class Piping Construction Management Engineer : 1


Chief Electrical Engineer : 1


Class-2 Welding Supervising engineer : 3


Operations Chief of Gas Welding :1


Operations Chief of Oxygen Deficient Danger : 23


Operations chief of assembling, etc., of scaffolding : 7


Operations Chief of Radiography with Gamma-rays : 1


Liquid Penetrant Testing LEVEL2 : 2

Ultrasonic Inspection (Second type) :1
Safety and Health Supervisor : 3


Rust Prevention Management Engineer : 1


Qualified Water Tank Cleaning Worker : 4


Fall Protection Competent Person : 3

   (per EM385-1-1)


Water Supply Equipment Chief Engineer : 1

Main Clientele

Nansei Sekiyu K.K.

Okinawa Plant Kogyo Company,Inc

Air Self‐Defense Force on Okinawa

Jpec Ishikawa Company

Tec Project Service Co.Ltd

Shinko Plantech Co., Ltd.

JFE Engineering Corporation

CB&I Federal Services


Okinawa Electric Power Company, Inc

Okinawa Prefectural Enterprise Bureau

Maritime Self Defense Force on Okinawa

Toyo Engineering Corporation

JGC Corporation

Mitsubishi Chemical Engineering Corporation

DLA-Energy Okinawa

Weston Solutions, Inc.

Recent Construction Achievements

<NSS-Related works> ※NSS: Nansei Sekiyu K.K.

1 Periodic maintenance works

 ①Refinery tower overhaul inspection and maintenance

 ②Higher pressure gas and hazardous object related plumbing replacement

  and new construction

 ③Heating Furnace overhaul inspection and lining

 ④Heat exchanger overhaul inspection, tube bundle replacement

 ⑤Catalyst discharging and charging for reactor

 ⑥Periodic Safety valve inspection

 ⑦Various Inspection and maintenance for Petroleum Products manufacturing facilities

2 Oil Tank Overhaul Inspection (hazardous material / high pressure gas ) through the year

 ①Legal safety inspection

 ②Base plate・side plate・roof replacement

 ③Internal tank cleaning, other tank-related maintenance works

3 Project Works (new construction・remodeling)

 ①32 inch crude oil plumbing repair (2009)

 ②Oil heating plumbing installation (2010)

 ③Foam fire extinguisher and heating system equipment installation for TK-1100 (2012)

 ④Marine oil facilities works for berth 1(2012-2013)

 ⑤Remodeling of oil products (Gas Oil / Naphtha) exclusive line plumbing for forwarding


 ⑥Kerosene/JP-4 plumbing repair works for forwarding (2014)

 ⑦Various other projects

4 Various routine maintenance / construction works

 ①Static device and rotary machine

 ②Instrumentation equipment

<Projects on U.S. bases in Okinawa>

1 Repairs to 505th's pipelines from Tengan to KAB. (2008)

2 Repairs to POL pipeline bridges at KAB and Valve Boxes (2008-2009)

3 Storage Tank Cleaning (2009)

4 Maintenance of 505th Cathodic Protection Wiring Wiring (2009-2010)

5 Repairs to Chimu Wan Tank Farm #3 drainage and Valve Box removal (2010-2011)

6 Repair Underground Pipeline Phase I, Thermal Relief 505th Quartermaster Battalion,

  Okinawa, Japan (2012-2013)

7 Repairs to POL Facilities on KAB (2013)

8 Repairs to Able Electric and Drainage Lines on KAB (2014)

9 Repairs to Fuel Tanks at Kadena Air Base, Okinawa

10 Preventive Maintenance of Real Property Fixed Equipment for DLA(2014-2015)

11 Repairs to Baker Tank 1 on Kadena Air Base(2014-2015)

12 MCAS Futenma Fuels Storage Facility Repairs To Tank 639(2014-2015)

13 Cleaning, Inspection Support, and Repairs to three tanks in Kuwae Tank Farm#2


Recent Construction Achievements

<OEPC Makiminato Pipeline Works>

 ※OPEC: Okinawa Electric Power Company, Incorporated.

1 Okinawa CIP (※Cross Island Pipeline) repair work / inspection (2008)

2 Okinawa CIP safety inspection work (2010)

3 Okinawa CIP plumbing repair work (2011)

4 Safety inspection work (2012)

5 Okinawa CIP plumbing repair work  (2012)

6 Okinawa CIP safety inspection work  (2013)

7 Makiminato Pipeline plumbing repair work (2014)

 ※Cross Island Pipeline from Makiminato Thermal Power Station to Nansei Sekiyu K.K.

<OEPC Ishikawa Thermal Power Station Works>

1 Waste drainage tray plate installment work at Coal Ash treatment plant connecting bridge (2006)

2 Coal Storage Ventilator Repair Coating (2006-2007)

3 Fuel oil tank overhaul inspection (2007)

4 Seismic resistance inspection for hazardous material storage facilities (2013)

5 Fuel oil and gas oil plumbing repair (2014)

6 Fuel oil tank overhaul inspection (2014-2015)

7 Salt corrosion removal and repair for oil detector at pump yard (2014-2015)

8 Hazardous material storage facilities repair (2014-2015)

<Public Works>

1 Winding staircase installation for Uehara Area Distribution Reservoir of Nishihara Town (2008)

2 Digital terrestrial antenna maintenance for Nishihara Town (2010)

3 Pressure surging electric room air conditioning unit replacement (2013-2014)

4 Lighting facilities repair for Japan Maritime Self Defense Force (2014-2015)

5 Water supply pipe repair for Japan Maritime Self Defense Force clinic tower (2014-2015)

6 Electromagnetic valve installment for Japan Air Self-Defense Force (2014-2015)

<Other works>

1 Naha Meat fuel tank replacement work  (2014)


NSK (Nanseki Kaihatsu) shipping agent is mainly supporting petroleum product ships stop at Nansei Sekiyu for safe and smooth entering to the port, loading, and a series of procedures on departure from the port.


We have over 15 years of experience dealing with government office, related

agencies, customs, quarantine, Immigration, Coast Guard, Okinawa General Bureau, and jurisdiction police station for administrative procedure for ships and crews and prompt correspondences. We provide latest information to shipowners and related ships, shift crews, provide shopping support, and handle emergency correspondences.


Furthermore, we provide crews and shipowners reliable services as a shipping agent while coordinating with Coast Guard and related agencies closely. We consider safety first, handling job quickly regarding on entering to and departing from the port.


We continue to improve our services to satisfy our customers, not only shipowners but also ships and crews to meet their needs as much as possible.