Indonesian government called Japan for the extension to the Jakarta-Bandung project. This surprised Japanese. They were surprised that Jakarta-Bandung project was given to Chinese and not to them in 2016. The current Jakarta-Bandung project is being build by KCIC a consortium of China and Indonesia companies.

As Ayo Bandung reports, a Japanese official said "Normally, Indonesia should talk to us first,". After surprisingly loosing Jakarta Bandung fast train project to China, Japan got 720km Jakarta-Surabaya railroad project in September 2019.

As Ayon Bandung reports,  Coordinating Minister for the Economy Airlangga Hartarto, revealed that President Joko Widodo proposed to extend the Jakarta-Bandung railroad project to Surabaya to be 'more economical', and bring Japanese investors to join the project. done by Indonesian-Chinese investors in a press conference on May 29, 2020.  This has surprised the Japanese who felt they were passed over on the Jakarta-Bandung project.

https://ayobandung.com/read/2020/06/29/100249/jepang-bingung-mendadak-diajak-gabung-proyek-kereta-cepat-indonesia