Johyo (memorial to the emperor) was an act of handing Monjo (written material) (or Hyo [letters]) or the Monjo itself to the Emperor from any Koshin (Emperor's family) including Togu (crown prince), all the officials or general public.
If the person who did Johyo was a male, they addressed themselves as '臣' and if they were females they used '妾', and the beginning of their sentences were to have '臣(妾)某言' and their endings were to have '臣(妾)某誠惶誠恐頓首頓首死罪死罪謹言' (Yours faithfully). These letters were handed to the Emperor through the Nakatsukasasho (Ministry of Central Affairs) and Daijokan, the highest organ of state affairs had no involvement.
There were three major different types of Hyo: Gahyo (handed at celebratory occasions such as Emperor's Genpuku [coming of age], investitures of the Empress or the Crown Prince and Sakutan Toji [celebration when the winter solstice falls on November 1 of the lunar calendar. Once in 19 years, this is an auspicious day and has been celebrated at the court]), Kohyo (handed when the Emperor's family members wished to decline the Emperor's offer of abdication of the throne or people to decline the offers of privileges such as Fuko [salary] or Zuishin [having bodyguards]) and Jihyo (handed when people wished to resign or leave their government posts). Under the Senjoryo (the regulations for the recruitment and promotion of government officials), when government officials (nobles) of Jugoinoge (Junior Fifth Rank, Lower Grade) and over wished to resign his positions, they had to get the Emperor's permission; so it became a custom that they wrote a Jihyo when nobles resigned from government posts. On the other hand, after the mid Heian period, Gahyo and Kohyo lost its significance and people started not to do these anymore, 'Johyo' became the same meaning as Jihyo. At that time, handing over a Jihyo became more like a ritual and the procedure of Johyo was carried over as a part of Yushoku-kojitsu (knowledge of court rules, ceremonies, decorum and records of the past). For the officials in high positions such as Sekkan (Regent to the Emperor), it became a custom in which, Johyo was handed three times: the first two times, the Emperor asked for dissuasion from resigning or leaving and handed it back and the third time he made a decision (whether to accept the Johyo and the resignation or hand it back to reject the resignation). The first and second Johyo presented with formality were called 'Shodo' (first time) and 'Dainido' (second time); and the third one, the Emperor actually decided his answer, was called 'Daisando' (third time). Later, when a newly appointed minister was to take up his new position, he was expected to present Johyo just before that and he had to do it until it was returned to him three times.
There were quite a few cases of Johyo (Jihyo) recorded in the Heian period. In 808, when FUJIWARA no Otsugu was appointed as the Tosando Road Supervisor, he handed Johyo three times on June 1, 21 and December 17 but his request of refusal was not accepted ("Nihonkoki" [Later Chronicle of Japan]). In 995, when Kanpaku (chief adviser to the Emperor) FUJIWARA no Michitaka handed his Johyo three times on February 5, 16th and April 3, due to illness, his resignation was accepted. Also, when FUJIWARA no Michinaga was the Nairan sadaijin (minister of the left who has a right to read and deal with documents before reporting to the Emperor from Daijokan, the Great Council of State), he handed his Johyo on April 27, May 9 and 18 due to his illness, it was temporarily accepted until his recovery, and on July 16, when Michinaga recovered, it was cancelled ("Gonki" [FUJIWARA no Yukinari's Diary]). As for Johyo presented by a newly appointed minister, before the appointment, when FUJIWARA no Sanesuke was to be the new Udaijin (Minister of the Right) in 1021, he handed Johyo on June 16, 22 and 26 and all were returned; then he was appointed to the position on July 25 ("Shoyuki" [the diary of FUJIWARA no Sanesuke]). When FUJIWARA no Koretane became very ill, the Emperor Enyu accepted Johyo from a Sessho (Regent) straight away and FUJIWARA no Naritoki criticized this dishonorable behavior (that the Emperor did not wait until he received the third Johyo).