5.2 Ryanmen
A ryanmen is two consecutive suited tiles waiting on either end. 12 and 89 lack one end, so they are not ryanmen.
34-sou becomes a 234-sou sequence with 2-sou, or 345-sou with 5-sou.
Its waits cover two kinds, up to 8 tiles. That is the most of the five shapes.
A kanchan like 35-sou waits only on 4-sou. If you can reach tenpai with either, you choose the ryanmen.
Discard one tile to leave a ryanmen wait.
You picked . Discarding it does not reach tenpai.
A 34-sou ryanmen is left. The waits are 2-sou and 5-sou.
Discarding 3-sou leaves a 46-sou kanchan. The only wait is 5-sou.
Discard one tile to leave a ryanmen wait.
You picked . Discarding it does not reach tenpai.
A 56-man ryanmen is left. The waits are 4-man and 7-man.
Discarding 5-man leaves a 68-man kanchan. The only wait is 7-man.
Discard one tile to leave a ryanmen wait.
You picked . Discarding it does not reach tenpai.
A 67-sou ryanmen is left. The waits are 5-sou and 8-sou.
Discarding 6-sou leaves a 79-sou kanchan. The only wait is 8-sou.
Discard one tile to leave a ryanmen wait.
You picked . Discarding it does not reach tenpai.
A 45-sou ryanmen is left. The waits are 3-sou and 6-sou.
Discarding 4-sou leaves a 57-sou kanchan. The only wait is 6-sou.
Discard one tile to leave a ryanmen wait.
You picked . Discarding it does not reach tenpai.
A 23-pin ryanmen is left. The waits are 1-pin and 4-pin.
Discarding 2-pin leaves a 35-pin kanchan. The only wait is 4-pin.