I can answer the question about Korea.

The Korean Empire built the first rail lines in Korea starting in 1896. The Seoul-Incheon line, aka the Gyeong-in line, was originally to be built by an American company, but within months of starting the project, the rights were sold to a Japanese company. Kyung Moon Hwand writes in A History of Korea:

In hindsight it was clear that the Japanese had eyed this short stretch as the prelude to the larger prize of building two "trunk lines" that would extend from the capital to the port city of Pusan in the southeast and to Uiju in the northwest. These two lines, with the former completed in time to aid the Japanese effort against Russia in the 1904-5 war, would greatly aid Japan's expansionist aims.

The Gyeongin line started at Noryangjin Station and continued west southwest through:

• Yeongdeungpo
• Oryu-dong
• Bucheon
• Bupyeong
• Juan
• Chukhyeon (currently Dongincheon)

This line was an important link between Jemulpo port (present day Incheon) and Seoul. A national road, the 46 (Gyeongin-ro) parallels the train line from Yeongdeungpo out to Incheon and the train line was merged into the Seoul subway system on August 15, 1974. This was the day that the Seoul Subway first opened, but it is overlooked because August 15 is Liberation Day and on that day in 1974, an assassin took a shot at Park Chung-hee but instead killed a student and President Park's wife during a speech. But I digress...

The names of the train lines are all a combination of the terminal cities. "Gyeong" means capital, so all lines with "gyeong" in the title go to Seoul. The Gyeongin line connected the port of Incheon to Seoul, where the Gyeongbu (Busan), the Gyeongui (Sinuiju), and the Gyeongwon (Wonsan) lines met up. The Japanese built the Gyeongbu line and it was finished by January 1905, allowing Japanese troops and supplies to take a ferry from Shimonoseki Japan to Busan, and then take a train up to Seoul. The Gyeongui line was finished near the end of 1905, giving the Japanese a rail line over 900 km from Busan to the Chinese border.

Between 1910 and 1945, the Japanese built the majority of the rail infrastructure in Korea. The three main lines are the Gyeongbu, the Honam, and the Jungang line. The Gyeongbu line (mentioned above) has many minor lines connecting up with it, as well as the Honam line, which runs from Daejeon (central South Korea) through the Jeolla region to Mokpo, a port city on the southwest coast. It was built between 1911 and 1914. Some of the other lines which connect to the Gyeongbu are:

• Janghang line (Cheonan to Janhang) - 1922
• Anseong line (Cheonan to Icheon) - 1925, shut down in the late 80's
• Chungbuk line (Jochiwon to Bongyang, on the Jungang line) - 1921
• Gyeongbuk line (Gimcheon to Jeomcheon) - 1921, to Andong - 1937

There are a few other short sections - the Daejeon line connecting Daejeon and Seodaejon Stations, the Daegu line, connecting the Gyeongbu and Jungang lines for a few miles, etc.

On the Honam line, the Jeolla line connects Iksan and Yeosu and was built between 1914 and 1936. The Gyeongjeon line connects Gwangju to Miryang, a city north of Busan on the Gyeongbu line. It was built from 1905 to 1968.

So, what did KOREA actually build?

Not much. After independence, the railway lines were nationalized and placed under the KRNA, Korea Rail Network Authority. Under Park Chung-hee and the Supreme Council for National Reconstruction, a series of 5 year plans were realized to develop the country economically. As part of this, many rail projects happened. The aforementioned Gyeongjeon line was completed. At the time, the line had a gap of about 50 miles between Jinju and Suncheon. Due to the geography, it required numerous bridges and tunnels to complete and it finally opened in 1968, after 5 years of construction (10 miles a year, while the Gyeongbu line was completed in only 2 years, crossing the whole of South Korea).

The bulk of the train work though was done in the east. Gangwon-do got the Yeongdong line, built between 1940 and 1962. This line was crucial for moving coal from the mines to the Jungang line and into Seoul. The Taebaek line was also built to develop coal mining and connects the Yeongdong line and the Jungang line. It was built from 1955 through 1973 and has what was at the time the longest tunnel in Korea. These days, the line carries mostly cement and tourist passengers. The Taebaek line even has it's own spurs, the Hambaek and Jeongseon lines, both which served mining and logging in the Taebaek mountains of Gangwon-do. Further, some of the lines in Chungbuk and Gyeongbuk got extensions or realignments, namely the Gyeongbuk line which had the section from Jeomcheon to Andong ripped up for the war effort.

In short, to answer the question, yes, there was a lot of development by the Japanese prior to independence. The KRNA only built a fraction of the existing conventional train lines in Korea.

Part I ( Part II will be just below this reply)

But before I focus specifically on Japan I will adress this point

My personal belief is that Taiwan's rail system, being similarly well run today, owes some of that to the mindset it inherited from that period.

I do agree and it is back by research , works touching on the history of punctuality in Asia are very few, with a notable exception of an excellent work by the Taiwanese historian Liu Shaoli (Shuiluo Xiangqi: Rizhi Shiji Taiwan Shehuide Shenghuo Zuoxi which translated into "Sound of Steam Siren: Work and Leisure in Taiwan in the Period Occupied by Japan") which discusses the history of punctuality in Taiwan during the time of Japanese occupation.

Now to reframe your first question: How, then, did the Japanese were able to acquire a sharper sense of time over the past century and a half? How did they come to acquire and take for granted punctuality? How did they come to pursue efficiency and productivity?

Well I am happy to tell you that there was already an investigation on this broad questions, a collaborative and interdisciplinary study was organized for the academic year of 1999 and 2000 at the International Center for Japanese Studies in Kyoto. The study resulted in a collection of papers titled Chikoku no Tanjō(the Birth of Tardiness)

Prior to the launch of this collaborative research project, academics had naturally assumed that several modern institutions introduced from the West must have worked to facilitate the implementation of punctual and efficient behavior

Of them, three key institutions— schools, factories, and railroads—were investigated. Since the early Meiji period, punctuality has been strongly encouraged at these institutions. For new primary school students, for instance, the Ministry of Education issued the Seito Kokoroe (Direction to Elementary School Children) in 1873 with the following precepts:

Make sure that you are at school ten minutes before the start of class every day. If you are late for school, do not enter the classroom without permis-sion; explain the reason for your tardiness and wait for your teacher’s instructions

These were explicit and fairly strict instructions for innocent children. They were issued at the time that Japan changed from its traditional calendar using seasonal time to the Western calendar using clock time; it is certainly doubtful that students actually followed the rule and attended school in time. Some episodes tell us that the reality was far from this ideal.

Even so, it can be conjectured that the emergence of the new school system officially emphasizing punctuality to students was highly significant in promoting punctuality in society through the creation of new generations of younger people who were at least conscious of the importance of punctuality.

Under the government’s modernizing policy, the first railroad opened at the same time, and its lines were swiftly constructed with the assistance of British engineers. However, with the increase of railroad lines and complexity of their operation, the delay of trains in fact became a problem.

The following statement, made in 1901(Cited in Naofumi Nakamura, “Railway Systems and Time Consciousness in Modern Japan,” in The Birth of Tardiness, op.cit., p. 30.) vividly expresses the lamentable situation of the private railroad lines.

Recently, trains belonging to privately owned railway companies depart or arrive late all the time. Almost all trains are behind schedule, with rare exceptions, and station staff who should give the first priority to maintaining time never seem concerned about delays, having given up on being punctual and acting as if delays were somehow inevitable. With some railways, almost no trains run on schedule, while others use timetables as a kind of hint indicating that trains will arrive behind schedule. Furthermore, delays are not a matter of a mere five or ten minutes, but rather it is unusual for them to extend up to thirty minutes or even an hour…. The cause of the delays is that Japanese, both those running the railroads and the passengers, are, owing to bad old customs, lacking the turn of mind that observes time strictly…

These statement as well probably answered your second question ("Was the the public perception of the rail system always like it is today?")

To ameliorate the situation, railroad officials and engineers required stricter discipline from railroad workers. They constructed double- track lines, studied time and motion, and changed to the automatic coupling system throughout the entire railroad network, which was entirely new even compared with the railroad in the West And thanks to the engineer Okiie Yamashita, they succeeded in greatly reducing the time consumed for the inspection and repair of locomotives.

In attempting to introduce the techniques of scientific management to Japan, some experts became sharply aware that the establishment of punctuality was essential to further modernize the management of Japanese factory systems. In his effort to introduce Taylorism to a naval arsenal, Takuo Godō explicitly stated that punctuality was a premise for the introduction of more advanced scientific management, and his words implicitly indicated that Japanese workers were in reality still unfamiliar with punctual working attitudes and Japanese managers were not yet ready to introduce fully the method of Taylorism. Godō, however, subsequently succeeded in introducing Taylorism to Japanese naval arsenals, as well as in introducing the technologies of the limit gauge system.

Through these efforts, time discipline and punctuality became well established at railroads and lets not forget as well as at arsenals and private factories in pre- war Japan.