Hatsune Hatsune D.C. is 26 episodes, starting from Junyi and kurotsuchi nemu, who are just in grade 3, and ending in grade/kloc-0 of our headquarters, and then kurotsuchi nemu went to nursing school for further study.
D.C.S.S is 26 episodes, about two years after D.C., kurotsuchi nemu returned to Hatsune Hatsune in the sixth episode, and finally Junyi married kurotsuchi nemu.
The above is the first generation of Hatsune Hatsune, which is relatively old. Only in recent years has the second generation of animation appeared.
D.C.2*** 13 episode, 53 years after the first generation, the protagonist is Sakuchi Yoshiyuki, who was born after Yoshino Sakura made a wish on the magic cherry tree (not the last one). Others include asakura Junyi and Asakura Nemu's granddaughters, asakura Youmeng and Asakura Yoshi, both in the third grade attached to Feng Jian Academy, who ended up with the graduation of robot Tiancang Meixia. This is mainly about Yihe Moon Island.
D.C.2SS.S is the last film, episode *** 13, and the plot shifts from college life to the magical cherry tree. In order to prevent the cherry tree from realizing its bad wishes, Yoshino Sakura and the elderly asakura Junichi successively merged into the cherry tree to act as "inner desire filters", which disappeared, but still could not stop the harm. Asakura Yoshi had to let the cherry tree wither, and the meaning of wishes began to disappear.
In short, there is not much connection between the first generation and the second generation, which can be said to be two different stories. The only constant is Yoshino Sakura, which remains the same after 53 years.
At this point, the story of Hatsune Hatsune Island is all over.