Together

Together is a Youko ending and one of 25 possible fourth episodes in Shiny Days.

Plot
''As this ending can be achieved coming from two very different branches, the plot varies depending on which branch is taken. The scenes in Paris, however, are identical, including Makoto's arrival at the airport.''

Via 33322
The plot of Together via 33322 is nearly identical to Paris for Two (via 33322) or Gift From My Father up until Makoto's departure for Paris, except for that after Setsuna depart for Paris, if Makoto doesn't force himself on Kokoro on the beach, the following scenario is always taken.

Some time passes after Setsuna leaves for Paris. Makoto and Ai are shown having sex at the Radish, where she has taken up Setsuna's previous position. Ai is happy that she and Makoto are finally connecting, but she soon finds out that she and Makoto have very different ideas about what their relationship is.

Ai is stunned to find out that Makoto is planning to go to Paris to reconnect with Setsuna and that he has only been waiting for his passport to be approved. She says that everyone thought they had broken up, and that she and Makoto were a couple now. Makoto replies that Setsuna is still his girlfriend, and he explains that what he and Ai had been doing was just sex. He thanks her for keeping him company over the time Setsuna was gone. Ai is crushed as he goes to the airport.

Via Fruition
Some time passes after Setsuna leaves for Paris. Hikari and Ai are eating at Radish and talking with Sekai about what happened between Makoto and Setsuna. Hikari say that she`s sure that it`s Makoto fault, Sekai tries to defend him, but get teased by Hikari, who also says that nobody would like Makoto. Hikari then mention that Nanami is in training camp for basketball team. Ai realizes that Katou is out of town, but then Hikari says that they going to return tomorrow, so Ai panics, leaves Radish, and goes to Makoto. She is able to meet him, but he`s in a hurry, and when she asks what it`s about, Makoto answers that he needs to go where his beloved is.

Makoto Arrives in Paris
Youko takes a confused Setsuna to the airport and tells her that she's here to meet someone she knows. Youko points out the gate he'll be coming from, and Setsuna is stunned when Makoto walks towards them. He stops, seeing Setsuna standing there, and simply says, "I love you." On the verge of tears, Setsuna echoes his sentiments, and starts to run toward him when Youko brushes past her, overjoyed, and wraps her arms around Makoto. Both Setsuna and Makoto are surprised by this, as Youko expresses her gratitude that he came for her and that she loves him. Makoto, clearly unsure what to do, stammers an agreement. Setsuna is unable to process what she's seeing and freaks out.

Route
There are two routes to Together: one from 33322, and one from Fruition. Both require that Makoto has previously entered a relationship with Youko, making episode 2 Drowning in Secrets.

Via 33322
Getting Together via this route requires the aforementioned criteria be met, and that Makoto have high affection for Setsuna by the time she leaves for Paris.(i.e. the bar must be high)

Also the requirements for endings Substitute or Rain of Carnage or Paris for Four shall not be met.

If episode 2 was Part-time Job, you will get the ending From Kotopi to Se-chan\Paris for Two\Gift From My Father instead.

Via Fruition
Getting Together via this route requires the aforementioned criteria be met, and that Makoto have high affection for Setsuna by the time she leaves for Paris (i.e. the bar must be high).

If episode 2 was Part-time Job, you will get the ending Paris for Two instead.

Trivia
In the English release, the title was translated to Together. However, in the original release, the title is 共に有らん, which actually means not together.