Shorinji Kempo (少林寺拳法) literally translates to Shaolin Temple martial arts; however, contrary to what English wikipedia page suggests, it has nothing to do with Shaolin Kunfu (少林功夫).
The fact that So Doshin (宗道臣), born Nakano Michio (中野理男), fabricated the origin of Shorinji Kempo is a public secret. There has been various sources pointing out inconsistencies of Nakano's writings. It is likely true that Nakano did go to Manchuria and China during the Pacific War. The book 'Hiden Shorinji Kempo' (秘伝少林寺拳法) describes how he met Chen Lian (陳良) and Wen Taizong (文太宗), but his first wife has apparently testified that they were neighboring grocers. The style he claimed to have learned is Yihe quan (义和拳).
Also in the book, Nakano claims that in 1936 he has gone to Shaolin Temple with Wen was given masterhood of Yihe quan in front of Abbot Shi Henglin (释恒林). Even though Nakano's martial art is not Shaolin style, that still sounds interesting if it were true. The problem is that the famous Abbot Henglin had died in 1923.
Here's a likely historical account. In 1948, Nakano joined Hakkoryu (八光流) a style of Jujutsu. He started his own school in 1949 named Nihon Hokuha Kempo Kai. A novel was published in 1950 mentioning Shaolin style martial arts where he could have learned about it.
In 1951, Nakano started Sohonzan Shorinji, Religious Corp (宗教法人総本山少林寺). In 1963, Nakano publishes 'Hiden Shorinji Kempo' claiming to be the only heir of Shaolin quan sifu in Japan, and soon afterwards the number of students increases dramatically.
In 1973 Shorinji Kempo sues Fudozen Shorinji Kempo (不動禅少林寺拳法) in Osaka based on 'Unfair Competition Prevention Act' (trademark infringement). The case, known as 昭和48年（ワ）1491号, was rejected by Supreme Court, and ended up exposing Nakano and Shorinji Kempo as a fraud. One of the inconsistencies pointed out was Neijia quan ("internal" quan) like Yihe quan would not have lineage along "external" quan Shaolin quan. When Nakano took the witness stand, it was pointed out that the passage that describes Shaolin Temple in 'Hiden Shorinji Kempo' book was a ripoff from another book 嵩山旅行記 (Song Shan Travels) by Masuda Kisaburo (増田亀三郎). On the stands, he was not able to produce any credible description of the place or a person who might remember him.
After Nakano's death in 1980, his daughter So Yuki (宗由貴) takes over as the president. In 1993, Shorinji Kempo settles with Fudozen Shorinji Kempo by paying them 70 million yen (~USD 678k) in exchange for forcing Fudozen to rename to Shorinjiryu Kempo (少林寺流拳法). Afterwards, Shorinji Kempo has stopped claiming to have any Chinese martial arts origin. So Yuki even appeared in a tv show Trivia No Izumi (トリビアの泉) admitting that Shorinji Kempo was invented in Kagawa (香川県) in Japan, not China, and that there's no relationship whatsoever to Shaolin Temple (Japanese transcript).