Jiroemon Kimura - 116 years, 54 days, Japan
Jiroemon Kimura is currently the world’s oldest ever man in the validated lists. He was validated scientifically by a Japanese team  and is one of the few other cases which we consider to have been validated to a standard comparable to the “gold standard” applied to Jeanne Calment. Since Calment’s case is nevertheless disputed due to an unresolved switch scenario, it is now also necessary to ask if the case of Kimura is sufficient to eliminate any ambiguity in his record.
One difficulty with Japanese claims as explained by Kimura’s validators is that vital records are not public. To access records the validators must approach the family for permission. In this case the validators were able to obtain birth, marriage and death data for all Kimura’s siblings and children with only a few missing gaps. These are helpfully listed in the validation report. This should be a requirement for any scientific validation.
The validators confirm that the original koseki from his parental family were used, and that other records including his graduation from elementary school were also available.
Using these lists and the background information provided, we have the ability to identify any potential opportunities for an in-family identity switch. Kimura had a brother five years younger whom he visited in Korea for a period of five months to care for him while he was sick. The date of this brother’s death is missing but he is assumed to have died at 85. This provides the first potential opportunity for a swap with the brother. Kimura’s oldest son died at the age of 76 when Kimura was 103. This offers a second potential opportunity for a switch.
Kimura’s validators draw attention to the possibility of switches in the introduction to their report. They also identify the specific period around when he visited his brother as one where a swap might be possible. They dismiss this based on testimonial evidence of Kimura and his family. However, not many details are given on these crucial points. In general, photographs can also help rule out switch scenarios, but in some cases more information is needed. Unfortunately, even the DNA evidence can’t rule out the potential early life sibling swap.
Some additional information was provided by the validators in 2020 . The new material focused on his life testimony, but it also clarified which documents had been found, and it showed copies of the original Koseki. This is very helpful for those who want to check the validation.
We learnt that Kimura cared for his sick brother in Korea just before he got married. It is impossible to completely rule out some age exaggeration or even an identity switch, but this validation reduces the probability of a false validation as far as is possible within the difficult Japanese system by supplying a large amount of useful information.