▪ The name of the event is Strawberry Picking, but the chapters of the story are labeled as "Strawberry Colored Holiday"
Titles and Honorifics
-dono: That honorific that particularly humble or traditional characters use. If you watch anime that are set in the Meiji era (or older) you may be familiar with this. Shinobu uses this since he's a ninja otaku, as does Souma, as he's the traditional type.
Character Speech Patterns
Shinobu tends to speak in somewhat archaic forms, while simultaneously sounding childish (he's fond of onomatopoeias, for example). He likes to use sessha (a humble and old way of referring to yourself), and even uses some old forms (such as using -nu instead of -nai for negatives). These are really hard to portray in translations outside of making him speak as humble/polite/archaic as I could, so I'm mentioning them here.